@1tuffcookie
Safety device. If you fall off the back or side of the device, it instantly turns off the motor when it disconnects from the unit as you fall.
Can't really tell on this one, but where it attaches to the machine is usually an electro- magnet.
If that magnet loses contact the machine immediately stops.
They seemed to indicate the magnet side of the cord HAD to be connected. Whether you connect the other end to yourself doesn't seem to matter. The magnet is what stops the machine.
Shawn probably didn't have it clipped on because she was on and off it so much in the demo.
I'd read the reviews of this model.