Spoilers ahead. Great job on putting this together! I got 40/60 on paintings. Some of the signs for me were that if it just pops a little too much (very bright brights) it's probably MidJourney. I also saw some give aways that would be very strange choices for a human artist. One ai painting had two signatures, another had an extra piece of arm that didn't belong, extra fingers, one had the eyes closed and not in a particularly artistic way, I also saw misshapen eyes. Another one had an ink pen in her hand while an ink pen was still in the holder. Also lack of detail in particular areas where you would expect more attention to detail. Also, if I could zoom in and still see shapes of distant figures that made sense, or small supporting objects that was pretty clearly an old master. For example, there was one that had venetian boats and guys holding the poles, but also a random pole stuck in the mud. After thinking about it, this seems a very likely way to store them and not some random ai choice. In another, it looked very much of da Vinci, but the face was incredibly detailed and life like, which I never recalled seeing from his drawings. I also had some success with noticing that if the scene just felt cropped, where some supporting detail felt like it needed to be extended, that tended to be an old master. That said, if it was a straight portrait or a particularly stylized painting it was hard to tell. There was a man made of vegetables that had incredible detail and another person made of detailed flowers. One was AI, the other was not. Very impressive.