It shouldn't come as much of a surprise that LeBron James rolling to the hoop is effective. It also shouldn't come as a surprise that it's an even more effective play when Kyrie Irving is handling the ball.
When the Cavs run pick and rolls with James and Irving, it puts defenses in a catch-22 situation. If they don't defend LeBron tightly as he rolls, he's probably going to get two clean points at the rim. And if they sag off Irving, there's a pretty good chance he'll take advantage pf even a little bit of space.
Here the Magic gave LeBron way to much room to roll in and he made them pay with a powerful two-handed slam. Again, this shouldn't be much of a surprise.