On the other hand, pausing a film/game automatically when you leave the room would be a nice feature, if configurable and overrideable.

it's not a good feature, it's just a gimmick, a good feature would be it pause if and only if I tell it to(vocally would be nice).

Also, I'm pretty sure it would make me feel uneasy having machines reading me all the time and making decisions on what should I probably want it to behave like "Oh Breno is watching a QOTSA concert, he left to grab a beer, I should probably pause" that's sort of goofy, but the matter is: it doesn't know what I want.. it's a shitty feature

I'll call this type of gimmick "smartass technology"

I'm pretty sure there's a design/usability guide that supports what I'm saying...

You could trick it with a picture of a happy family watching TV in front of it. Bathroom breaks all around!