Index: wp-includes/css/admin-bar.dev.css
===================================================================
--- wp-includes/css/admin-bar.dev.css	(revision 17488)
+++ wp-includes/css/admin-bar.dev.css	(working copy)
@@ -192,6 +192,8 @@
 }
 
 #wpadminbar .quicklinks li#wp-admin-bar-my-account-with-avatar > a img {
+	width: 16px;
+	height: 16px;
 	display: inline;
 	border: 1px solid #999;
 	vertical-align: middle;