There could be a few places it's leaking from there.
First of all, was the bike down on this side? It looked from the other pics it was dropped on the other side, but in this pic it looks to me like the foot shifter is bent. If so, the shift shaft that goes into the engine (or whatever it's called) could be bent, damaged, leaking, etc.
Anyway, that oil leak could be oil leaking from the primary cover case (that large black case that mates to the silver engine). I believe there's just a gasket between the two pieces. Also it could be trans mission oil leaking from the transmission cover/plate (look just above the rubber part of the foot shifter, there is a small plate with three screws in it, that's where the transmission fluid goes, there's a gasket there). Only other possibility I could see is there are oil lines on top of the muffler, below the engine, that run from front of engine to the swingarm, they could be leaking onto the muffler then running down the side of the muffler and dripping. I doubt this last one though, I don't think there are any connections in the lines in that area, there'd have to be a rip in the line to cause a leak.