There are some demos in the Docs [1] linked from the README, but I believe that's still very useful feedback. I will pass it along. Thank you!
I know this is common with projects that think Github is a replacement for a website, but I genuinely wonder how does it get so bad that a 5 year project with 9000 commits and 60 contributors doesn't have a single screenshot. Nothing personal or particular about this project specifically, just... the whole open source culture of dropping something on Github and not even doing the bare minimum to have other people get to know the project.
It feels like such a waste. It could be an amazing project but who is going to bother with it if they can't see what it looks like?