This is cut and dry. Grab the cable handle and walk away from the machine. Keep your elbow in one position and extended your arm to a full extension.
This is a very good finisher movement and is also good for the prevention of elbow injuries.
The bands are added to this movement because the eccentric portion with 3-4 pulley machines is 1/2 to 1/4 what it should be. The band is added to make up this difference as well as providing more tension at the end of the movement.