I don't know where the photographer was, and in person I could show you exactly how the punch looks, because it is weird to modern eyes.
One of the most important factors is the external rotation of the lead leg, in this case, the left knee. The toes would point relative to wherever the opponent is. So envision this opponent was moving slightly away from Ray's right hand. Ray would correspondingly shift his lead foot so his toes faced the opponent's center, and likely shift a bit of weight to that foot (albeit so subtly the opponent wouldn't detect his head coming a bit closer). Prior to this all the weight would be on the back foot, so that right as that lead foot got into position and the weight started to move, he'd drop that back knee, turn his heel, and fire the right all at the same time. The external rotation of the lead knee provides an angle for the punch that allows a lot of defensive liability without needing the hands. He can do anything off of the punch. The lead foot moves, back foot corrects itself. His left hook is loaded (left hip), or he can push off that left foot and move back, he could shift back onto his right foot and throw another right, or either of the uppercuts. It looks odd to us because the follow-up movements are pre-loaded.