Launch your bird up with the angle shown. You want to hit the target so that it weakens the structure which helps to trigger the bomb. It should also be noted that you will need to destroy enough blocks on top of killing all the pigs to get the three star mastery.
Power Activation Point
Activate the laser power so that it bounces off the metal surface shown in the picture. It has to bounce off the metal surfaces twice to trigger the bomb. If you destroy the wooden blocks enough, the falling pieces may detonate the bomb as well.
First Shot Result
With the bomb detonated, it destroys the structures and killing all the pigs. You will then earn the title of three star master for the stage.