Projecting them to lasers which are already attached in the room.
It's not clearly stated but it seems likely that the intention is to disable the lazers that are not horizontal.
By doing so it reduces the 3d-grid/matrix created by the lazers at the ceiling pointing down leaving only the horizontally pointing lazers which Viginia can avoid with her gymnastics.
My (non-technical) understanding of this sort of laser security system is that it functions by detecting when a beam is interrupted and tripping an alarm.
On one end of the room is a laser projector, directly across from that is a sensor. If the sensor ever fails to detect the beam that should be pointed at it, the alarm is sounded.
Robert sets up his own laser beam projectors and points them at the receiving sensors, so that even if the real beam gets interrupted, the sensor won't realize it (because it's still sensing light from the "fake beam.")