Upvote:2
The green / red is an indicator that it is your turn to approach the window to speak with the agent. When you approach the border you are supposed to stop outside the booth lane, then proceed to the window on green.
Not sure about the "right", as I have never seen that light before. I would guess that it means go to the right lane (by the small booth shown).
All the other equipment there is cameras, radioactivity detectors and other sensors.