Ok, I had to speak up on this one because I think we might be missing a very obvious possibility (unless of course this has been mentioned before and I missed it): Perhaps Mr. J is the one pulling a gun on a "look-a-like" goon, instead of the other way around. The "gunman" in the picture is too blurry to really make him out... That would explain why we don't see makeup under the mask that is in the foreground... because it's really on the man in the background.
Just a thought...
I always thought Heath was Joker in the purple suit in the back...
...then I saw the spy photos of him wearing the suit of the guy in the front.
It's real f***ing confusing.