FWIW, I don't think that's an "arm." :D
That “thing” on the left is very suspicious, certainly not an arm, as you said! Before taking the photo, the photographer should have shouted, “Your fly is open!!”
Maybe the picture was taken for posterity. LOL!
Which gay guy is this?
The hand and fingers seen above Obama’s left knee (and below his right shoe) are clearly from Obama’s left hand. How do I know? Because the hand holding the cigarette is a right hand (look at the index finger and thumb; BTW, it’s one, not two hands, with the bent thumb creating the illusion of being parts of several fingers), so it must belong to the guy with the mustache, leaving Obama’s left hand unaccounted for. And it can’t be the case that Obama’s left hand is hidden, because the hand above Obama’s knee can’t be the mustached guy’s left hand, either, since one can clearly see the mustached guy’s left wrist (with the watch) and it’s way too far away from the hand and fingers above Obama’s knee.
That being said, Obama could well be a Friend of Dorothy anyways . . . .