Lawrence, that is a second Aladdin joystick. If you are at mid coach and have the TV on, set to the correct input, you can see what is a copy of your Aladdin monitor's screen, and control it the same as the joystick by the driver's seat. You'll have to try the different inputs by using your TV remote control until you find the Aladdin signal input, just like if you change input from TV to your DVD or other component. Turn on the Aladdin power at a joystick first, so you'll recognize the input when you get to it.
If the TV is on and set at the right input, pressing either the driver's or galley joystick up will turn on your Aladdin monitor and bring it up on your TV. Press right to select from any menu, and left to go back. Some rigs have another control alongside the bed, so you can monitor things via the bedroom TV, even seeing behind the coach via the backup camera if you awake to strange noises outside.
Your control looks like it's missing the proper knob. It probably got broken off by a previous owner. If necessary a person could fabricate one out of wood to glue over the shaft, but my old eyes can't tell from your photo if there's much joystick shaft there to work with.
Joel
