Wikipedia and Commons appear to be introducing a new image viewer which doesn't actually load a new page when clicking on an image, e.g. clicking on the featured image on the Commons main page takes me to http://commons.wikimedia.org/wiki/Main_Page#mediaviewer/File:Origanum_vulgare_-_harilik_pune.jpg not http://commons.wikimedia.org/wiki/File:Origanum_vulgare_-_harilik_pune.jpg