> That's because it's the sensor that allows the skybridge to automatically level itself when the plane moves up and down on its suspension due to fueling, load

> That's because it's the sensor that allows the skybridge to automatically level itself when the plane moves up and down on its suspension due to fueling, loading, unloading, etc. And if you pay attention while you're on the jetbridge, it's not entirely uncommon to feel it move as it adjusts. (Although I find the movement a bit disconcerting, even though I know it's normal.)