Index: wp-content/themes/twentytwelve/style.css
===================================================================
--- wp-content/themes/twentytwelve/style.css	(revision 21626)
+++ wp-content/themes/twentytwelve/style.css	(working copy)
@@ -333,7 +333,7 @@
 	line-height: 2;
 	color: #777;
 }
-.wp-smiley,
+img.wp-smiley,
 .rsswidget img {
 	border: 0;
 	border-radius: 0;