> What cool problems did you (not the robot) solve?

Building products has nothing to do with technical problems, just the end result. This is in contrast with things like writing a library or coming up with a new algorithm, or doing research, or even writing a technical blog post, etc.

> or is it just pretty?

People have been sharing "just pretty" things on HN for decades. It might be interesting, thought-provoking, discussion-worthy, or whatever. Even if this wasn't vibe-coded, it wouldn't be some monumental technical achievement. Your point is absolutely moot.