So the idea is to have the option to control the opacity or transparency of the picture-in-picture window, to have a transparent floating video window can help in many cases.
Even if not available as an option directly on the PiP, I was disappointed to see that it wasn't even an option in the about:config menu. Opacity control would absolutely make this one of my favorite features (even if it's already pretty high up there).
Hello to whoever read this, I would love to see a Transparent mode for the Picture in Picture feature on Firefox just like Opera GX. I use PiP at work all the time so having it not blocking/obscuring contents would be a great quality of life feature. Thank you.