diff -u b/core/modules/media/src/Plugin/media/Handler/Image.php b/core/modules/media/src/Plugin/media/Handler/Image.php
--- b/core/modules/media/src/Plugin/media/Handler/Image.php
+++ b/core/modules/media/src/Plugin/media/Handler/Image.php
@@ -128,7 +128,7 @@
     }
 
     // Get the file, image and EXIF data.
-    $file = $this->getSourceFieldValue($media);
+    $file = $this->getSourceFile($media);
     $uri = $file->getFileUri();
     $image = $this->imageFactory->get($uri);
 
@@ -196,7 +196,7 @@
    * {@inheritdoc}
    */
   public function getThumbnail(MediaInterface $media) {
-    return $this->getSourceFieldValue($media)->getFileUri();
+    return $this->getSourceFile($media)->getFileUri();
   }
 
   /**
diff -u b/core/modules/media/tests/src/FunctionalJavascript/ImageTest.php b/core/modules/media/tests/src/FunctionalJavascript/ImageTest.php
--- b/core/modules/media/tests/src/FunctionalJavascript/ImageTest.php
+++ b/core/modules/media/tests/src/FunctionalJavascript/ImageTest.php
@@ -2,12 +2,10 @@
 
 namespace Drupal\Tests\media\FunctionalJavascript;
 
-use Drupal\field\Entity\FieldConfig;
-use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\media\Entity\Media;
 
 /**
- * Tests for Image Media type.
+ * Tests the image handler plugin.
  *
  * @package Drupal\Tests\media\FunctionalJavascript
  *
@@ -16,54 +14,6 @@
 class ImageTest extends MediaHandlerTestBase {
 
   /**
-   * Create storage and field instance, attached to a given media type.
-   *
-   * @param string $field_name
-   *   The field name.
-   * @param string $field_type
-   *   The field storage type.
-   * @param string $type_id
-   *   The media type machine name.
-   */
-  protected function createMediaField($field_name, $field_type, $type_id) {
-    $storage = FieldStorageConfig::create([
-      'field_name' => $field_name,
-      'entity_type' => 'media',
-      'type' => $field_type,
-    ]);
-    $storage->save();
-
-    $config = FieldConfig::create([
-      'field_storage' => $storage,
-      'bundle' => $type_id,
-    ]);
-    $config->save();
-
-    // Make the field visible in the form display.
-    /** @var \Drupal\Core\Entity\Display\EntityFormDisplayInterface $form_display */
-    $component = \Drupal::service('plugin.manager.field.widget')
-      ->prepareConfiguration($field_type, []);
-
-    entity_get_form_display('media', $type_id, 'default')
-      ->setComponent($field_name, $component)
-      ->save();
-  }
-
-  /**
-   * Helper to create a set of fields in a media type.
-   *
-   * @param array $fields
-   *   An associative array where keys are field names and values field types.
-   * @param string $type_id
-   *   The type machine name.
-   */
-  protected function createMediaFields(array $fields, $type_id) {
-    foreach ($fields as $field_name => $field_type) {
-      $this->createMediaField($field_name, $field_type, $type_id);
-    }
-  }
-
-  /**
    * Just dummy test to check generic methods.
    */
   public function testMediaImagePlugin() {
reverted:
--- b/core/modules/media/tests/src/FunctionalJavascript/MediaHandlerTestBase.php
+++ a/core/modules/media/tests/src/FunctionalJavascript/MediaHandlerTestBase.php
@@ -52,7 +52,7 @@
     // Make sure the provided fields are visible on the form.
     if (!empty($provided_fields)) {
       foreach ($provided_fields as $provided_field) {
+        $assert_session->selectExists("field_mapping[$provided_field]");
-        $assert_session->selectExists("field_map[$provided_field]");
       }
     }
 
@@ -70,4 +70,27 @@
     return MediaType::load($type_name);
   }
 
+  /**
+   * Helper to assert presence/absence of select options.
+   *
+   * @param string $select
+   *   One of id|name|label|value for the select field.
+   * @param array $expected_options
+   *   An indexed array of expected option names.
+   * @param array $non_expected_options
+   *   An indexed array of non-expected option names.
+   *
+   * @see \Drupal\Tests\WebAssert::optionExists()
+   * @see \Drupal\Tests\WebAssert::optionNotExists()
+   */
+  protected function assertSelectOptions($select, $expected_options = [], $non_expected_options = []) {
+    $assert_session = $this->assertSession();
+    foreach ($expected_options as $expected_option) {
+      $assert_session->optionExists($select, $expected_option);
+    }
+    foreach ($non_expected_options as $non_expected_option) {
+      $assert_session->optionNotExists($select, $non_expected_option);
+    }
+  }
+
 }