>>49587153I believe it's looking for is spikes and a color scheme with a lot of different colors. If you look at what it declares the Most Pokemon Pokemon, you can see that they're mostly rounded with one major color.
I think it's odd how many Gen 3 Pokemon show up here though. Maybe it's a result of the change in art styles from Gen 3 on influencing the weighting of what it what it sees as a Pokemon.
