Index: wp-content/themes/twentytwelve/style.css
===================================================================
--- wp-content/themes/twentytwelve/style.css	(revision 21494)
+++ wp-content/themes/twentytwelve/style.css	(working copy)
@@ -982,7 +982,7 @@
 /* =Single image attachment view
 -------------------------------------------------------------- */
 
-.image-attachment div.attachment {
+.image-attachment div.attachment p {
 	overflow: hidden;
 	text-align: center;
 }