Said when someone attempts to do something related to their right side when you have just told them to do it with their left side. Sometimes mildly condescneding.
"You've got some food on the left side of your face. No, your other left"
it means Right (the direction) because there can't be 2 Lefts
Person 1: Dude, the mens bathroom is on the left
Person 2: here?
Person 1: No man, the other left...
Person 2: ahhhh, i get it, you mean my right?
Person 1: yes...