Shane is using a standard break from the box. He's just really good at it. His timing through the ball is very precise and this is where the effortless appearance comes from. That's hundreds of hours of break practice that he has put in to achieve that.
The reason the cue ball jumps back off the rack and ends up back in the center is because of two opposite forces working against each other. The cue ball banks off of the rack forcing the cue ball toward the break box but the forward spin that is acquired causes the cue ball to come forward a little. When these forces work against each other in this fashion you get a "kill" reaction on the cue ball, which gives you the effect that you see in the video.
If you're working on your break you should know that you need to develope it over time. I don't believe that you can just get up and start hitting them harder and get good results. Concentrate on your timing rather than speed. You can increase your speed as you go. You also need to make sure that you're hitting the head ball as full as possible to get the optimum reaction.