When you do pullovers with a band, the band keeps adding tension throughout the range while the resistance from gravity diminishes as the lever arm shortens. All told, this causes your muscles to have to work harder for longer. That means more muscle growth.
Finally, a warm-up routine that even people who hate warming up can handle! This short series of drills will not only make you feel better, but the increased mobility you'll gain will help you make unprecedented gains in the gym.