I know you're joking, but I think the former has to do more with facial features/structure and the latter is more a case of demeanor (not that it actually invol

I know you're joking, but I think the former has to do more with facial features/structure and the latter is more a case of demeanor (not that it actually involves attempts to cause death through eye contact, just that it's different and unsettling to some). Probably the overlap is when the death glare is more noticeable.