Well, one big thing I see is that the only textual clue that you have wallpaper that does not require paste and is not hung on the wall is the word vector in your tag cloud. Keep in mind, you have to think like a somewhat dumb computer that can not read visual clues and must rely on the actual text to decide what the site is truly about.
no its not. Google do not hate wallpaper websites. ofcourse its a form of websites and people do like it. Moreover you will get a lot of extra traffic from images.