In some Salsa moves, you want to make a different movement pattern. In a Basic Step, the leader and follow go into the same direction on the dansfloor (leader forwards, follower backwards). With the Open Break, you go into opposite directions. In the first move, you both step backwards, creating tension in the arms (called “boing”, like the springy sound, in the lessons). The next move you move towards each other.
This is used in a variety of moves. See Enchufla Doble for example.