diff --git a/core/modules/image/image.admin.inc b/core/modules/image/image.admin.inc
index b736b18..84c5dc0 100644
--- a/core/modules/image/image.admin.inc
+++ b/core/modules/image/image.admin.inc
@@ -109,9 +109,8 @@ function template_preprocess_image_style_preview(&$variables) {
     $variables['preview']['original']['height'] = min($variables['original']['height'], $sample_height);
     $variables['preview']['original']['width'] = round($variables['preview']['original']['height'] / $variables['original']['height'] * $variables['original']['width']);
   }
-  $variables['original']['style'] = 'width: ' . $variables['preview']['original']['width'] . 'px; height: ' . $variables['preview']['original']['height'] . 'px;';
 
-  // Set up preview file information.
+  // Set up derivative file information.
   $preview_file = $style->buildUri($original_path);
   // Create derivative if necessary.
   if (!file_exists($preview_file)) {
@@ -131,7 +130,6 @@ function template_preprocess_image_style_preview(&$variables) {
     $variables['preview']['derivative']['height'] = min($variables['derivative']['height'], $sample_height);
     $variables['preview']['derivative']['width'] = round($variables['preview']['derivative']['height'] / $variables['derivative']['height'] * $variables['derivative']['width']);
   }
-  $variables['derivative']['style'] = 'width: ' . $variables['preview']['derivative']['width'] . 'px; height: ' . $variables['preview']['derivative']['height'] . 'px;';
 
   // Build the preview of the original image.
   $variables['original']['rendered'] = array(
@@ -142,12 +140,12 @@ function template_preprocess_image_style_preview(&$variables) {
     '#attributes' => array(
       'width' => $variables['original']['width'],
       'height' => $variables['original']['height'],
-      'style' => $variables['original']['style'],
+      'style' => 'width: ' . $variables['preview']['original']['width'] . 'px; height: ' . $variables['preview']['original']['height'] . 'px;',
     ),
   );
 
-  // In the preview, timestamps are added to prevent caching of images.
-  // Build the preview of the image style.
+  // Build the preview of the image style derivative. Timestamps are added
+  // to prevent caching of images on the client side.
   $variables['derivative']['rendered'] = array(
     '#theme' => 'image',
     '#uri' => $variables['derivative']['url'] . '?cache_bypass=' . $variables['cache_bypass'],
@@ -156,7 +154,7 @@ function template_preprocess_image_style_preview(&$variables) {
     '#attributes' => array(
       'width' => $variables['derivative']['width'],
       'height' => $variables['derivative']['height'],
-      'style' => $variables['derivative']['style'],
+      'style' => 'width: ' . $variables['preview']['derivative']['width'] . 'px; height: ' . $variables['preview']['derivative']['height'] . 'px;',
     ),
   );