When two friends make a bet. Instead of the loser having to pay money, they have to change their Facebook profile picture. However, they do not change it to just any picture. The loser of the bet signs on to Facebook and goes to their profile page. On the left side of the page are pictures of 6 friends (pictures are in a 2 by 3 rectangle). The loser then must change their profile picture to who ever popped up in the left upper-most corner of the 2 by 3 rectangle of friends. They must keep the picture for some pre-set amount of time.
The loser has one "page refresh" so they can they have a second chance of who pops up in the friends box.
Durn, I lost Bruno's Facebook Bet and then I had to change my profile picture to this girl I literally just met the other night. She probably thinks I am a huge creep. The worst part was that all my close friends kept commenting on it and "liking" it so that everyone would see.