I remember there being some Android phone (some generation of Samsung Galaxy S series probably) with a "feature" where it pauses video playback if you look away from it. Good thing it didn't catch on.
S10+ here. I'll have to check and see what my older phones still have, my current one still has "keep screen on while viewing", I don't think I had one that paused videos, but I remember one offering "smart scrolling" based on eye movement
Side note: If I'm wearing headphones, and you don't know me, and you disturb me without a good reason, I won't hurt you or anything, but know that you're a bad bad person.