Tony appeared to "see himself" due to (IMHO, and until I am convinced otherwise,) a bad edit. Whether that edit was intentionally purposely ambiguous or not, I don't know...
I just replayed the scene several times, and I don't see him "seeing himself". When he's looking at the table, there is nobody sitting at the table. He does go from standing in the door, to sitting down at the table in a split second though.
You're right, JL. Tony walks in, looks around (and doesn't see himself) and then must sit down when the camera flashes back and shows him sitting in the booth (a few seconds later).
