[warpech]

This is the Picture-in-Picture API it implements: https://w3c.github.io/picture-in-picture/

I am surprised that the API is modelled to only allow watching videos in PiP, while the old and mature Fullscreen API allows to put any element in full screen. These should be analogous. I don't see a reason why I can run a <video> in a small window, but not a <canvas> a <picture>, etc.

[mconley]

As the article mentions, Firefox is not currently implementing the Picture-in-Picture Web API that you linked to. Firefox's implementation is a browser feature only, and not exposed to the web at large.

[joaobeno]

Not "API", and Mozilla intends to vote against, I hope...