Edmo, just as an FYI, the narrator of the film Natalinana is referring to is actually the Uncle of Mohammed. Mohammed's image is never shown in the film except for the controversial scene in which shows one of his eyes.
I am not sure if this is the move you are thinking of but one that came to mind from your description is The Savage Eye. Gary Merrill is the narrator throughout the move. However, I don't recall if his image is ever shown.
The Savage Eye (1960) - IMDb If this isn't the one you are thinking of, it is definitely worth checking out if you have the time. Excellent movie.
I am also left wondering if you are possibly thinking of a television episode of Tales From the Crypt. The episode is entitled "You, Murderer". The main character is the narrator who sounds like Humphrey Bogart. It is filmed from his point of view & you never see the guy, EXCEPT when he is looking at his reflection and when that happens, archived images of Humphrey Bogart is in the reflections. They did a great job of interweaving those images. Very fun episode. It also starred the wonderful John Lithgow & Isabella Rosselini.
"Tales from the Crypt" You, Murderer (1995) - IMDb user reviews