diff --git a/wp-includes/css/media-views.css b/wp-includes/css/media-views.css
index 98d96a07c8..8b1283f4ae 100644
--- a/wp-includes/css/media-views.css
+++ b/wp-includes/css/media-views.css
@@ -566,18 +566,33 @@
 	cursor: default;
 }
 
-.attachment-details-preview,
-.attachment-details-preview .thumbnail {
+.attachment-details-preview {
 	width: auto;
 	height: auto;
-	float: left;
 	position: relative;
 }
 
-.attachment-details-preview .thumbnail img {
-	max-width: 120px;
-	max-height: 120px;
+.attachment-details-preview .thumbnail {
+	width: 100%;
+	height: auto;
+}
+
+.attachment-details-preview .thumbnail:after {
+	content: '';
 	display: block;
+	position: absolute;
+	top: 0;
+	left: 0;
+	right: 0;
+	bottom: 0;
+	box-shadow: inset 0 0 0 1px rgba( 0, 0, 0, 0.1 );
+	overflow: hidden;
+}
+
+.attachment-details-preview .thumbnail img {
+	display: block;
+	max-width: 100%;
+	max-height: 132px;
 	margin: 0 auto;
 }