Used when you get off topic and you shouldn't be, in large groups. A nicer way of saying, "Shut up and get back to work!"
Person 1: So... We should get to work on the giant project due tomorrow
person 2: So yesterday I went shopping and I saw this cool shirt and I wanted to get it.
Person 3: Oh, that's so cool, I think I bought the same shirt!
Person 2: Really?
Person 1: ICE BOX!