Asking for Trouble

Taunt GLaDOS in front of a camera in each of the five co-op courses. Every course has GLaDOS cameras on the walls; stand in front of one and throw any gesture. You need one in all five courses - Team Building, Mass and Velocity, Hard-Light Surfaces, Excursion Funnels and Mobility Gels - so tick each off as you clear it, or you'll be trekking back for the one course you forgot.