Named for the film director Stanley Kubrick, who made at least eight movies where a major character has this facial expression. When some other show or film uses it, it’s frequently a homage to Kubrick. Generally it symbolizes that the character in question is either really, really pissed or really becoming deranged, and the person they’re looking at is really, really screwed. Other times—usually when combined with a smile—it means they’re feeling really, really clever. Either way, it’s really creepy and ominous. Although depending on the context, it can also be very Badass.