With my jaw…
The end result is, as far as your monitor is concerned, indiscernible from a photograph. I mean, the guy literally worked on the highlights of each mole. I’ve seen many, many instances of trompe l'oeil in my life and some of it is mind-bending in its attention to detail.
When I was taking art courses in college (hey, I originally wanted to write software like Photoshop. Figured I needed to know color theory and whatnot) there was a sister class doing trompe l'oeil. One guy did a light switch that he put on the wall and it fooled every person who walked in the room. There was another guy who took a mishmash of random objects and attached them to a board. Although the arrangement was dada in nature, from anything more than a foot away, it was impossible to tell the painting from the real (when they were both set up under lights).
An interesting thing though – realism at this level is an art in an of itself, but honestly – the end result is no more pleasing to the eye than a real photograph. And several of the other students I took classes with had amazing abilities to draw realistically, but couldn’t create a moving piece of art if you commissioned them.
I dated a girl like that. She had the uncanny ability to draw exactly what she could see. But nothing she ever did had any feeling. It was sterile. You could appreciate the technical skill it took to make something that realistic, but it didn’t move you. And she absolutely could NOT draw anything that she couldn’t see with her eyes. If I recall, she went on to be a medical illustrator, which made a lot of sense.
Still, that’s simply amazing to watch, especially knowing this is nothing but an app from the Apple store and a finger.