Index: src/wp-includes/js/tinymce/skins/wordpress/wp-content.css
===================================================================
--- src/wp-includes/js/tinymce/skins/wordpress/wp-content.css	(revision 27340)
+++ src/wp-includes/js/tinymce/skins/wordpress/wp-content.css	(working copy)
@@ -80,6 +80,8 @@
 .mce-content-body img.mce-wp-nextpage,
 .mce-content-body img.mce-wp-more {
 	border: 0;
+	-webkit-box-shadow: none;
+	box-shadow: none;
 	width: 95%;
 	height: 10px;
 	display: block;