diff -u b/core/includes/entity.inc b/core/includes/entity.inc
--- b/core/includes/entity.inc
+++ b/core/includes/entity.inc
@@ -563,21 +563,62 @@
   return entity_render_controller(reset($entities)->entityType())->viewMultiple($entities, $view_mode, $langcode);
 }
 
-
 /**
- * Returns an entity_display object for the view mode.
+ * Returns the entity_display object configured for a bundle and view mode.
+ *
+ * The function reads the entity_display object from the current configuration,
+ * or returns a ready-to-use empty one (with no cmponent set to be displayed)
+ * if no display is currently configured yet for this bundle and view mode. We
+ * do not preemptively create new empty entity_display configuration entries
+ * for each existing entity type and bundle whenever a new view mode becomes
+ * available. Instead, the actual configuration entries are only created when
+ * an entity_display object is explicitely configured and saved. This function
+ * streamlines manipulation of entity_display objects by always returning a
+ * consistent object that reflects the current state of the configuration.
+ *
+ * Note that the entity_display is only actually used at render time if the view
+ * mode itself is configured to use dedicated display settings for the bundle
+ * (if not, the entity_display for the 'default' view mode is used intead).
+ * Thus, when fecthing the display object to use for rendering an entity, the
+ * field_get_actual_view_mode() function is used first to determine which
+ * display to load.
  *
- * The function reads the object from the current configuration, or returns a
- * new object if the display is not configured yet.
+ * In the much more frequent use case of assigning suggested display options
+ * for a field in a given view mode, the entity_display object for this view
+ * mode should be used directly, without using field_get_actual_view_mode(), in
+ * order to avoid inadvertently modifying the output of other view modes that
+ * might use the 'default' display too. Those options will then be effectively
+ * applied only if the view mode is configured to use them.
+ *
+ * Example usage:
+ * - Set display options for the 'body' field on article nodes in the 'default' mode:
+ * @code
+ * entity_get_display('article', 'node', 'default')
+ *   ->setContent('body', array(
+ *     'type' => 'text_summary_or_trimmed',
+ *     'settings' => array('trim_length' => '200')
+ *     'weight' => 1,
+ *   ))
+ *   ->save();
+ * @endcode
+ * - Get options used for the 'body' field when rendering an article node in 'full' view mode;
+ * @code
+ * $view_mode = field_get_actual_view_mode('node', 'article', 'full');
+ * $display = entity_get_display('node', 'article', $view_mode);
+ * $options = $display->getContent('body');
+ * @endcode
  *
  * @param string $entity_type
- *   Machine readable name of the content entity.
+ *   The entity type.
  * @param string $bundle
- *   Machine readable name of the content entity bundle.
+ *   The bundle.
  * @param string $view_mode
- *   Machine readable name of the content entity view_mode.
+ *   The view mode.
  *
  * @return \Drupal\entity\Plugin\Core\Entity\EntityDisplay
+ *   The current entity_display configuration object for the view mode.
+ *
+ * @see field_get_actual_view_mode()
  */
 function entity_get_display($entity_type, $bundle, $view_mode) {
   // Try loading the display from configuration.
diff -u b/core/modules/entity/entity.install b/core/modules/entity/entity.install
--- b/core/modules/entity/entity.install
+++ b/core/modules/entity/entity.install
@@ -10,8 +10,8 @@
 /**
  * Returns the raw configuration object for an EntityDisplay entity.
  *
- * The function reads from an existing CMI file if it exists, or creates a
- * fresh structure.
+ * The function returns the existing configuration entry if it exists, or
+ * creates a fresh structure.
  *
  * @param string $entity_type
  *   The entity type.
diff -u b/core/modules/entity/lib/Drupal/entity/Plugin/Core/Entity/EntityDisplay.php b/core/modules/entity/lib/Drupal/entity/Plugin/Core/Entity/EntityDisplay.php
--- b/core/modules/entity/lib/Drupal/entity/Plugin/Core/Entity/EntityDisplay.php
+++ b/core/modules/entity/lib/Drupal/entity/Plugin/Core/Entity/EntityDisplay.php
@@ -23,7 +23,7 @@
  *   config_prefix = "entity.display",
  *   entity_keys = {
  *     "id" = "id",
- *     'uuid" = "uuid"
+ *     "uuid" = "uuid"
  *   }
  * )
  */
@@ -69,7 +69,7 @@
    *
    * @var array
    */
-  public $content = array();
+  protected $content = array();
 
   /**
    * The original view mode that was requested (case of view modes being
@@ -117,6 +117,40 @@
   }
 
   /**
+   * Creates a duplicate of the EntityDisplay object on a different view mode.
+   *
+   * The new object necessarily has the same $targetEntityType and $bundle
+   * properties than the original one.
+   *
+   * @param $view_mode
+   *   The view mode for the new object.
+   *
+   * @return \Drupal\entity\Plugin\Core\Entity\EntityDisplay
+   *   The new object.
+   */
+  public function createCopy($view_mode) {
+    $display = $this->createDuplicate();
+    $display->viewMode = $display->originalViewMode = $view_mode;
+    return $display;
+  }
+
+  /**
+   * Gets the display options for all components.
+   *
+   * @return array
+   *   The array of display options, keyed by component name.
+   */
+  public function getComponents() {
+    $options = array();
+    foreach ($this->content as $name => $options) {
+      if (!isset($options['visible']) || $options['visible']) {
+        $options[$name] = $options;
+      }
+    }
+    return $options;
+  }
+
+  /**
    * Gets the display options set for a component.
    *
    * @param string $name
diff -u b/core/modules/entity/lib/Drupal/entity/Tests/EntityDisplayTest.php b/core/modules/entity/lib/Drupal/entity/Tests/EntityDisplayTest.php
--- b/core/modules/entity/lib/Drupal/entity/Tests/EntityDisplayTest.php
+++ b/core/modules/entity/lib/Drupal/entity/Tests/EntityDisplayTest.php
@@ -14,7 +14,7 @@
  */
 class EntityDisplayTest extends DrupalUnitTestBase {
 
-  public static $modules = array('system', 'entity_test');
+  public static $modules = array('entity_test');
 
   public static function getInfo() {
     return array(
@@ -24,12 +24,16 @@
     );
   }
 
+  protected function setUp() {
+    parent::setUp();
+
+    $this->enableModules(array('system', 'field'));
+  }
+
   /**
    * Tests basic CRUD operations on EntityDisplay objects.
    */
   public function testEntityDisplayCRUD() {
-    $this->enableModules(array('system', 'field'));
-
     $display = entity_create('entity_display', array(
       'targetEntityType' => 'entity_test',
       'bundle' => 'entity_test',
@@ -73,10 +77,8 @@
    * Tests entity_get_display().
    */
   public function testEntityGetDisplay() {
-    $this->enableModules(array('system', 'field'));
-
     // Check that entity_get_display() returns a fresh object when no
-    // configuration file exists.
+    // configuration entry exists.
     $display = entity_get_display('entity_test', 'entity_test', 'default');
     $this->assertTrue($display->isNew());
 
@@ -95,8 +97,6 @@
    * Tests the behavior of a field conponent within an EntityDisplay object.
    */
   public function testExtraFieldComponent() {
-    $this->enableModules(array('system', 'field'));
-
     $display = entity_create('entity_display', array(
       'targetEntityType' => 'entity_test',
       'bundle' => 'entity_test',
@@ -119,7 +119,7 @@
    * Tests the behavior of a field conponent within an EntityDisplay object.
    */
   public function testFieldComponent() {
-    $this->enableModules(array('system', 'field', 'field_sql_storage', 'field_test'));
+    $this->enableModules(array('field_sql_storage', 'field_test'));
 
     $display = entity_create('entity_display', array(
       'targetEntityType' => 'entity_test',
diff -u b/core/modules/field/field.install b/core/modules/field/field.install
--- b/core/modules/field/field.install
+++ b/core/modules/field/field.install
@@ -475,7 +475,7 @@
     }
   }
 
-  // Write CMI files for the entity display objects.
+  // Save the displays to configuration.
   foreach ($displays as $config) {
     $config->save();
   }
diff -u b/core/modules/field/field.module b/core/modules/field/field.module
--- b/core/modules/field/field.module
+++ b/core/modules/field/field.module
@@ -740,6 +740,9 @@
  *
  * @return string
  *   The actual view mode to use for this entity type and bundle.
+ *
+ * @todo Move this function over to the entity API when the underlying
+ * variable is moved to configuration files.
  */
 function field_get_actual_view_mode($entity_type, $bundle, $view_mode) {
   $view_mode_settings = field_view_mode_settings($entity_type, $bundle);
diff -u b/core/modules/field_ui/lib/Drupal/field_ui/DisplayOverview.php b/core/modules/field_ui/lib/Drupal/field_ui/DisplayOverview.php
--- b/core/modules/field_ui/lib/Drupal/field_ui/DisplayOverview.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/DisplayOverview.php
@@ -421,7 +421,7 @@
    */
   public function submit(array $form, array &$form_state) {
     $form_values = $form_state['values'];
-    $entity_display = entity_get_display($this->entity_type, $this->bundle, $this->view_mode);
+    $display = entity_get_display($this->entity_type, $this->bundle, $this->view_mode);
 
     // Collect data for 'regular' fields.
     foreach ($form['#fields'] as $field_name) {
@@ -430,7 +430,7 @@
       $values = $form_values['fields'][$field_name];
 
       if ($values['type'] == 'hidden') {
-        $entity_display->removeComponent($field_name);
+        $display->removeComponent($field_name);
       }
       else {
         // Get formatter settings. They lie either directly in submitted form
@@ -443,7 +443,7 @@
         elseif (isset($form_state['formatter_settings'][$field_name])) {
           $settings = $form_state['formatter_settings'][$field_name];
         }
-        elseif ($current_options = $entity_display->getComponent($field_name)) {
+        elseif ($current_options = $display->getComponent($field_name)) {
           $settings = $current_options['settings'];
         }
 
@@ -451,7 +451,7 @@
         $default_settings = field_info_formatter_settings($values['type']);
         $settings = array_intersect_key($settings, $default_settings);
 
-        $entity_display->setComponent($field_name, array(
+        $display->setComponent($field_name, array(
           'label' => $values['label'],
           'type' => $values['type'],
           'weight' => $values['weight'],
@@ -463,17 +463,17 @@
     // Collect data for 'extra' fields.
     foreach ($form['#extra'] as $name) {
       if ($form_values['fields'][$name]['type'] == 'hidden') {
-        $entity_display->removeComponent($name);
+        $display->removeComponent($name);
       }
       else {
-        $entity_display->setComponent($name, array(
+        $display->setComponent($name, array(
           'weight' => $form_values['fields'][$name]['weight'],
         ));
       }
     }
 
     // Save the display.
-    $entity_display->save();
+    $display->save();
 
     // Handle the 'view modes' checkboxes if present.
     if ($this->view_mode == 'default' && !empty($form_values['view_modes_custom'])) {
@@ -481,22 +481,21 @@
       $bundle_settings = field_bundle_settings($this->entity_type, $this->bundle);
       $view_mode_settings = field_view_mode_settings($this->entity_type, $this->bundle);
 
-      foreach ($form_values['view_modes_custom'] as $view_mode_name => $value) {
-        if (!empty($value) && empty($view_mode_settings[$view_mode_name]['custom_settings'])) {
+      foreach ($form_values['view_modes_custom'] as $view_mode => $value) {
+        if (!empty($value) && empty($view_mode_settings[$view_mode]['custom_settings'])) {
           // If no display exists for the newly enabled view mode, initialize
           // it with those from the 'default' view mode, which were used so
           // far.
-          $display = entity_get_display($this->entity_type, $this->bundle, $view_mode_name);
-          if ($display->isNew()) {
-            $display->content = entity_get_display($this->entity_type, $this->bundle, 'default')->content;
+          if (!entity_load('entity_display', $this->entity_type . '.' . $this->bundle . '.' . $view_mode)) {
+            $display = entity_get_display($this->entity_type, $this->bundle, 'default')->createCopy($view_mode);
             $display->save();
           }
 
-          $view_mode_label = $entity_info['view_modes'][$view_mode_name]['label'];
-          $path = field_ui_bundle_admin_path($this->entity_type, $this->bundle) . "/display/$view_mode_name";
+          $view_mode_label = $entity_info['view_modes'][$view_mode]['label'];
+          $path = field_ui_bundle_admin_path($this->entity_type, $this->bundle) . "/display/$view_mode";
           drupal_set_message(t('The %view_mode mode now uses custom display settings. You might want to <a href="@url">configure them</a>.', array('%view_mode' => $view_mode_label, '@url' => url($path))));
         }
-        $bundle_settings['view_modes'][$view_mode_name]['custom_settings'] = !empty($value);
+        $bundle_settings['view_modes'][$view_mode]['custom_settings'] = !empty($value);
       }
 
       // Save updated bundle settings.
diff -u b/core/modules/node/node.module b/core/modules/node/node.module
--- b/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -218,9 +218,10 @@
 function node_entity_display_alter(EntityDisplay $display, $context) {
   // Hide field labels in search index.
   if ($context['entity_type'] == 'node' && $context['view_mode'] == 'search_index') {
-    foreach ($display->content as $name => &$properties) {
-      if (isset($properties['label'])) {
-        $properties['label'] = 'hidden';
+    foreach ($display->getComponents() as $name => $options) {
+      if (isset($options['label'])) {
+        $options['label'] = 'hidden';
+        $display->setComponent($name, $options);
       }
     }
   }
diff -u b/core/modules/system/lib/Drupal/system/Tests/Upgrade/FieldUpgradePathTest.php b/core/modules/system/lib/Drupal/system/Tests/Upgrade/FieldUpgradePathTest.php
--- b/core/modules/system/lib/Drupal/system/Tests/Upgrade/FieldUpgradePathTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Upgrade/FieldUpgradePathTest.php
@@ -34,7 +34,7 @@
   public function testEntityDisplayUpgrade() {
     $this->assertTrue($this->performUpgrade(), 'The upgrade was completed successfully.');
 
-    // Check that the entity display configuration files were created.
+    // Check that the configuration entries were created.
     $displays = array(
       'default' => config('entity.display.node.article.default')->get(),
       'teaser' => config('entity.display.node.article.teaser')->get(),