I think I'd recommend OBS too, but I guess this is possible with an application I wrote.

If you want to install it, it is available on Flathub here.

edit: My webp video stopped loading for me, so uploaded a mirror to YouTube here

Thanks. It's really intended to solve picture in picture for any application, but it looks like it does exactly was OP was requesting too.

Thank you. I’ve been using it daily and I was starting to worry it was just me. Flathub shows all these installs but my traffic on Github has mostly just been clones without views.

You say “mirrored window” so do I understand that right that if its just a mirror, I can’t close the original window nor open this view without the original window?

It does have to stay open. I'm able to minimize the original window, but I don't know how well that will work across different versions of Linux. It does require an original window to mirror.

I mean still extremely cool stuff even if you can’t do that. That just would make it even cooler. Will install it later. :) Hyped to try that out. Such a nice idea

Thank you. I hope it seems useful and not too confusing to use.

It's only 1 line of difference from the examples, but I did multiple mirrors to get the winding.

color = vec4(color.g, color.b, color.r, color.a);

And from that video, I took a screenshot