What the hell is Hangover 2 all about?

Oh. My. God!  Todd Phillips, director of The Hangover Part II, debuted a strange new photo on Facebook and the Interwebs has gone crazy trying to figure out: What does this mean?  What happened to Zach's hair? Ed Helms has a face tattoo? And let's talk about the monkey in the room! It's wearing a Rolling Stone jacket.  This movie is not going to disappoint.  Hilarious!