Basically this helps you pull into the gate since there is no person on ground. My vision is those dots on the screen represent your position and they are blinking as you pull into the gate. When you need to turn left a little, the left side of the dots will blink and the right will be stationary and vise-versa. When you dont need to turn, they will both blink at the same time. When you get close to the point of stopping, the lights will blink out from the outer-most dot into the middle. Once they ALL blink out, that means stop.