At YouTube, the "Skip Ad" button overlaps the Picture-in-Picture butto...

1. Start with a fresh Firefox profile.

2. Visit some YouTube video, e.g. https://www.youtube.com/watch?v=_ieNRF9aeTU (Hopefully you get a pre-roll ad with a 5-second countdown and then a "skip ad" button. This is necessary to trigger this bug.)

3. Once it's available, click the "Skip Ad" button -- specifically, if it overlaps Firefox's Picture In Picture overlay-button, click an area where they overlap.

EXPECTED RESULTS:

• I'd like to skip the ad.

ACTUAL RESULTS:

• If I clicked an area where the buttons overlapped, then the Picture-In-Picture button eats the click. So when I wanted to skip the ad, I instead get a popped-out PiP ad.
• The first time I do this in a fresh profile, this is extremely likely to happen because our PiP button auto-expands to helpfully explain itself with some bonus text. Unfortunately this expanded button nearly entirely overlaps the "Skip ad" button.

See attached screencast showing this "first time in a fresh profile" experience. I hover/unhover the "Skip Ad" button a few times, and then finally I click it, and instead trigger PiP.

(mconley, I know you've got some familiarity with our PiP code & user-experience -- do you know if this is a known issue and if there's anything we can do here?)