When you search Google images, then click on one of the image results, if the page containing the image also contains a Flash plugin, and you have Flash 10.1 installed, then the image overlay and the sidebar are missing. <rdar://problem/8232081>
This was broken by bug 42338, http://trac.webkit.org/changeset/63452
Created attachment 62628 [details] Patch
http://trac.webkit.org/changeset/64095