So just took a look at IMDB for Michael Massee and he is listed as the actor who played "The man in the shadows of the post-credits scene".
Also someone else had posted a lightened version of a still from that scene and it is very obviously him (hairline is unmistakable).
So now is it or isn't it Michael Masse in the poster in the lobby of Oscorp?
I did find a quick clip of the Oscorp Lobby scene and guess what kiddies...?
Yes, Michael Masse is the man in the poster/holographic picture in the lobby of Oscorp, meaning that it was Norman Osborn visiting Dr. Connors during the after credit's scene.
So that begs the question of why the thunder and how it seemed he "disappeared" when the thunder struck. Easy answer is "for effect". Totally speculative answer is "to make some people think it's Mysterio".
So then how did he get in and out of that room?
Well he's supposed to be this super rich and powerful dude. I would imagine that he could buy his way in and out of that room. Yes it appeared that he entered/left from an area of the room that is different from where Connors came in, but that's subjective.
This is real simple at this point...
Masse is Osborn. Massee is the actor of the "shadow figure". The shadow figure is Osborn. Everything else was just for effect!
This does not disqualify the Chameleon as a possibility. It is completely possible that the Chameleon took the appearance of Osborn when visiting Connors is jail.
