Originally Posted by Failed

From what I understand about the video after reading various sources:

She was followed to the elevator by someone. The reason the elevator door didn't close is because that someone or someones were holding the call button, therefore keeping the elevator on that floor with the door open. That someone or someones knew there was a security camera in the elevator and knew not to move in front of the door. The woman apparently tried to reason with the person holding the call button several times, but they wouldn't release it. She panicked and tried to get the elevator to move by pressing all of the buttons. After some time, the person or persons convinced her to come with them and she left the elevator, they released the call button, and you can see the elevator closes and starts going to different floors again.

The appearance of her acting weird seems to be just a poor woman in a panicked state trying to get someone to release the elevator door so she could get the hell out of there.

*Edit - This is all just speculation of course, not fact.