Why does a drone fly with respect to the air in a moving car/airplane, but not in an elevator as shown in this clip: [What Happens If You Fly a Drone In An Elevator?](https://www.youtube.com/watch?v=DUGwdcgi2L8)

I understand that the drone will move at the same speed as a moving car/airplane. Therefore, you'd have no trouble controlling it. However, according to the clip, in the elevator the drone stays in the same position and not with the elevator. Thus, if you want the drone to fly inside the elevator, you have to fly it upward if the elevator is coming up and vice versa.