Well, a thumbnail will be drawn over the icon, so you can't tell what it would be...
Attaching a very small matroska audio file to this comment; Nautilus will try to create a thumbnail, and give up when it finds it can't (as there's no video.) It will then display a blank page icon, even though it recognises that it is a media file (well, it knows that totem can play it anyway.) ** Attachment added: "Matroska audio stream" http://librarian.launchpad.net/5898124/test.mka -- Some media files are not recognised as such (ogm, mkv, mka) https://launchpad.net/bugs/81122 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs