Did the Prisoner recognise the face in the mirror, the Colonel? It's likely that he did, and recognised that his own people are messing with him again in having put him in the situation he finds himself in. That's why he put his fist in the mirror, he wanted to hit back! Certainly at the end, when the Prisoner woke up on that operating table, he knew who the Colonel was, and that Seltzman's mind now inhabits a body perhaps not to his liking, the Colonels." The Prisoner was never in the presence to see him in The Village, nor been in ear shot to hear of the Colonel, so he couldn't have been aware of the Colonel's presence in The Village. Yet on the other hand, even if he had, we do not know what happened to the Prisoner between being forcibly taken from his home and being placed on the operating table. And yet we do know that the Prisoner's memory had been regressed back to the day he was due to hand in his letter of resignation. That all unpleasant memories of The Village had been effectively wiped from his mind. But then how are we to account for the fact that the Prisoner's memory of the Village returned so instantly? Once the Prisoner sees the face of the Colonel in the mirror, that he sees other things, and memories of The Village come flooding back as we see on the screen. However my wife came up with an alternative idea....... that when Professor Seltzman reversed the effect of his machine, in putting the Prisoner's mind back rightfully in his body, it reversed the effect of having had all unpleasant memories wiped from his mind, so that the memories returned.
Be seeing you