I am absolutely sure they can recognize at least a cat in a two-dimensional picture. Filou even looked on a screen on whihc slides (of himself ) were projected and tried to walk behind the screen and see whether the cat was there
And later, he sat on the desk and heard the click when the slide changed and began to look from the projector to the screen and again, from the projector (which made the click) to the screen.
You could literally see his little brain working