diff --git a/config/schema/google_vision.schema.yml b/config/schema/google_vision.schema.yml
index 884df2a..76f0c1a 100644
--- a/config/schema/google_vision.schema.yml
+++ b/config/schema/google_vision.schema.yml
@@ -21,3 +21,6 @@ field.field.*.*.*.third_party.google_vision:
     safe_search:
       type: boolean
       label: 'Safe Search'
+    emotion_detect:
+      type: boolean
+      label: 'Emotion Detection'
diff --git a/google_vision.module b/google_vision.module
index 5048265..915ba1e 100644
--- a/google_vision.module
+++ b/google_vision.module
@@ -65,6 +65,12 @@ function google_vision_form_field_config_edit_form_alter(&$form, \Drupal\Core\Fo
       '#description' => t('Detects and avoids explicit contents.'),
       '#default_value' => !empty($settings['safe_search']) ? $settings['safe_search'] : FALSE,
     ];
+    $form['emotion_detect'] = [
+      '#type' => 'checkbox',
+      '#title' => t('Enable Emotion Detection'),
+      '#description' => t('Detects and notifies if the image is a happy one.'),
+      '#default_value' => !empty($settings['emotion_detect']) ? $settings['emotion_detect'] : FALSE,
+    ];
 
     $form['#entity_builders'][] = 'google_vision_form_field_config_form_image_builder';
   }
@@ -84,6 +90,7 @@ function google_vision_entity_bundle_field_info_alter(&$fields, EntityTypeInterf
   foreach ($fields as $field) {
     if ($field->getType() == 'image') {
       $fields[$field->getName()]->addConstraint('SafeSearch');
+      $fields[$field->getName()]->addConstraint('UserEmotion');
     }
   }
 }
@@ -93,6 +100,7 @@ function google_vision_entity_bundle_field_info_alter(&$fields, EntityTypeInterf
  */
 function google_vision_form_field_config_form_image_builder($entity_type, FieldConfigInterface $type, &$form, FormStateInterface $form_state) {
   $type->setThirdPartySetting('google_vision', 'safe_search', $form_state->getValue('safe_search'));
+  $type->setThirdPartySetting('google_vision', 'emotion_detect', $form_state->getValue('emotion_detect'));
 }
 
 /**
diff --git a/src/Plugin/Validation/Constraint/UserEmotionConstraint.php b/src/Plugin/Validation/Constraint/UserEmotionConstraint.php
new file mode 100644
index 0000000..cd16489
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/UserEmotionConstraint.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Drupal\google_vision\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Checks that the node is assigned only a "leaf" term in the forum taxonomy.
+ *
+ * @Constraint(
+ *   id = "UserEmotion",
+ *   label = @Translation("User Emotion", context = "Validation"),
+ * )
+ */
+class UserEmotionConstraint extends Constraint {
+
+  public $message = 'Please upload a photo where you are smiling and happy';
+}
diff --git a/src/Plugin/Validation/Constraint/UserEmotionConstraintValidator.php b/src/Plugin/Validation/Constraint/UserEmotionConstraintValidator.php
new file mode 100644
index 0000000..a2d5581
--- /dev/null
+++ b/src/Plugin/Validation/Constraint/UserEmotionConstraintValidator.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace Drupal\google_vision\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\file\FileInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\google_vision\GoogleVisionAPI;
+use Drupal\Core\File\FileSystemInterface;
+
+/**
+ * Validates the UserEmotion constraint.
+ */
+class UserEmotionConstraintValidator extends ConstraintValidator implements ContainerInjectionInterface {
+
+  /**
+   * The Google Vision API.
+   *
+   * @var \Drupal\google_vision\GoogleVisionAPI.
+   */
+  protected $googleVisionAPI;
+
+  /**
+   * The file system.
+   *
+   * @var \Drupal\Core\File\FileSystemInterface.
+   */
+  protected $fileSystem;
+
+  /**
+   * Constructs a UserEmotionConstraintValidator object.
+   *
+   * @param \Drupal\google_vision\GoogleVisionAPI $googleVisionAPI
+   *  The Google Vision API object.
+   *
+   * @param \Drupal\Core\File\FileSystemInterface $fileSystem
+   *  The File System object.
+   */
+  public function __construct(GoogleVisionAPI $google_vision, FileSystemInterface $file_system) {
+    $this->googleVisionAPI = $google_vision;
+    $this->fileSystem = $file_system;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validate($data, Constraint $constraint) {
+    $field_def = $data->getFieldDefinition();
+    $settings = $field_def->getThirdPartySettings('google_vision');
+    // If the Emotion detection is on.
+    if (!empty($settings['emotion_detect'])) {
+      $value = $data->getValue('target_id');
+      if (!empty($value)) {
+        // Retrieve the file uri.
+        $file_uri = $data->entity->getFileUri();
+        if ($filepath = $this->fileSystem->realpath($file_uri)) {
+          $result = $this->googleVisionAPI->faceDetection($filepath);
+          if (!empty($result['responses'][0]['faceAnnotations'])) {
+            $joy = $result['responses'][0]['faceAnnotations'][0]['joyLikelihood'];
+            $likelihood = array('UNLIKELY', 'VERY_UNLIKELY');
+            // If the image is not a happy one.
+            if (in_array($joy, $likelihood)) {
+              drupal_set_message($constraint->message, 'warning');
+            }
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static (
+      $container->get('google_vision.api'),
+      $container->get('file_system')
+    );
+  }
+}