I've seen images bugging out in a bunch of threads today as well....crossing between posts and stuff. I can't remember which threads though.
Edit: That looks to me like the little "sheet of paper" next to the date posted got messed up and switched with a different file...try emptying your cache?
it's in this thread too, at least for me. the last 2 posts atm have that image where the page lookin thing should go.
edit: after i posted it's just my post that has it
firefox 1.5 beta 1, windows xp sp2