This is fun and showed up on Hackernews today https://github.com/lynnpepin/reso. This is a digital circuit programming language that uses unstructured 2D images (PNG format) for its code representation. I don't know of many other languages like this beside piet (https://www.dangermouse.net/esoteric/piet.html). Cellular automata kind of fit into this category more broadly though.

Came here to share this. I think the bigger category here is "multicoding", where the representational syntax with some aesthetic effect dualize to have computationally interpretable meaning: https://esoteric.codes/blog/chef-multicoding-esolang-aesthetics