This term comes from the film world. In a movie you may see a guy buy a girl a drink in a bar, and in the next scene they are seen having raw sex in a bed somewhere. That huge jump in the timeline is called a jumpcut. So in the street, when a guy spots a fine chick he simply says "jumpcut" and his partners will know to look for a fine chick somewhere.
two guys walk down a street. A girl approaches and one of the guys says "jumpcut", alerting his partner to her presence.