That's why I emphasized the manual testing component as well. Attaching a screenshot or video of a feature working to your PR is a great way to prove that you've actually seen it work correctly - at least once, which is still a huge improvement over it not actually working at all.

This might be useful when working on a low trust team but I can’t imagine doing that in my job, unless specifically working a poc or presentation.

Yes! This is something that I also value. Having demo gifs of before and after helps a lot. I have encountered situations where what I thought was a minor finishing clean up had an effect that I didn't anticipate. By including demos in the PR it becomes a kind of guardrail against those situations for me. I also think it is neat and generally helpful for everyone.

If someone opened a PR, and it obviously doesn’t work but they claim they tested it, maybe that’s ok for the first time.

The second time it happens they gotta go.

I would find the expectation that I need to attach a screenshot insulting. And the understanding that my peers test their code to produce a screenshot would be pretty demoralizing.