this one is a funny one it's norwegan so read the instruktion's here insted.
stare at the picture it look's normal,but if you stare long wery long it appears that something is wrong it's hard to find out what's wrong so stare about 2min. Or more:
http://www.tull.no/innhold/bilder/vi...&sort=&katID=6 did you se it well then gotcha
edit: oops sorry