After the 'Battery' icon flashes, a single bullet will strike the screen along with gunshot sound effects. After the 'Battery' icon flashes again, the bullet will fall aside.
Once the Trix starts, put your iPhone in your chest pocket. After you hear the gunshots, pick up the iPhone and show them the “damaged” screen. Once you've shown them the screen, really put on the act and let them know that danger might be lurking nearby...