You have to be a great shoot in order to get the full mastery in this stage. Aim your bird launch at the triangle stopped all the way on the right cliff.
Power Activation Point
As you are flying through all the pieces, activate your laser gun so that one of the laser will pass through the tiny metal gap. The laser must be able to kill the pig at the bottom of the cave.
First Shot Result
Your lasers should be able to kill the three pigs on the left. After your bird lands on the triangle stopper, all the metal pieces fall down and kill the other two on the right. You will then be awarded with the three star mastery ranking.