I’m simply stating that they are short videos. The fact that they can do more is secondary, platform specific, and gimmicky. You send that “love photo” to an android device, a PC, an older iPhone, etc it all falls apart and it’s literally just a short video again.
The ability to change the “cover image” doesn’t mean it’s meant to allow you to pick the perfect frame, that’s just a secondary feature. You’re still sending the entire short video along.