^That Load is constantly communicating with Unload every 20 seconds. well, not impossible, but do you see the person at Unload console always on the phone? Does the person collecting glasses have a headset? Nope.
This is how it works: They force everybody in a narrow path that goes right next to the person collecting glasses. They then take them from every rider. The end. Everything else, even the signs, are just deterrents. There might be a sensor on the exit ramp to detect glasses, but I saw no such device or modifications that suggest something of that nature was implemented.
They just collect the glasses. The end.