commit 81fa4de01f7585ed9c4c3e1383e07839799550e4
Author: Vince <vtieu7@gmail.com>
Date:   Wed Dec 23 13:10:59 2015 -0500

    Bug 35200 - HiDPI styling of .media-modal-icon gets overriden

diff --git a/wp-includes/css/media-views.css b/wp-includes/css/media-views.css
index c20c179..37145f2 100644
--- a/wp-includes/css/media-views.css
+++ b/wp-includes/css/media-views.css
@@ -2569,7 +2569,7 @@
   (-webkit-min-device-pixel-ratio: 1.25),
   (min-resolution: 120dpi) {
 
-	.media-modal-icon {
+	.wp-core-ui .media-modal-icon { 
 		background-image: url(../images/uploader-icons-2x.png);
 		-webkit-background-size: 134px 15px;
 		background-size: 134px 15px;