It looks as if the aggressive great white shark is attacking the cage, but that is not the case.
In fact, the incredible shark is chomping at great big chunks of tuna that are tied to a rope. As the great white shark grabs at the meat, it becomes temporarily blinded.
When the shark grabs the bait, it accidentally hit the cage side, and was confused and also unable to swim backwards, so it pushed forward and thus he broke the metal rail of the cage.
But unbelievably, there was one diver in the cage when this breach occurred. He wound up on the outside of the cage underneath it, thus was able to look down at two other great white sharks below.