This means that a spy for one team may signal his alliance partner’s robots (with non-powered signals such as flags). It was added in response to question Q803:
Q. It appears that several teams are planning to have their spy use non-powered signalling directly to the robot (e.g. flags or scan codes). Does G35 prohibit the spy, who is a member of team BlueA, from using the signals provided by team BlueB during teleop, and if so, which robot is disabled?
A. A spy may signal an ALLIANCE partner’s ROBOT from the SPY BOX with a non-powered signalling device. G35 will be edited in Team Update 10 to reflect this.
Since the operator console is required to be contained in the driver station, I think the rule refers to the human player in the spy box sending signals to the robot via vision.