Can anyone else verify this? As every single ePub I have that has an iTunesArtwork file does not have that file listed in their manifest. It has just been inserted by iTunes in the same way that it inserts the .plist file.
I understand that "in theory" someone could create an ePub and modify their manifest to point the cover to it, but I am more interested in this "does this really happen" than the theoretical. In theory people can do all sorts of dumb-ass things to their ePubs.