A couple of other possibilities are that someone can control the elevator remotely, and can observe the interior of the elevator live through the security camera.
Or it's Elisa pushing the button from the outside to open and close the door several times at the end of the video. Like you would if the elevator door hadn't closed the first time.
I wonder on which side of the camera the hall elevator button is located.
If it's on the left, it could be Elisa, because thats the way she came and left.
If it's on the right, it's not her doing, it's someone else's doing.
And she was gesturing to the right, although she was looking both right and left down the hall.
Based on the photos of the hall, it appears that the
elevator button is on the left (looking out of the elevator), the side of the elevator that Elisa enters from and stands on when she exits. When you look out of the elevator you can see the horizontal "beam" on the opposite wall. This runs under the wall mirror. To the right on that same wall you can see the vertical white beam. this is what makes me think that this is the right-side elevator (again, looking out).
I have no idea why the elevator door doesn't close while she is standing inside the elevator. That is strange.
Regarding the door opening and closing in the last part of the video, I believe that the elevator is now moving down to different floors. Watch the lighted buttons on the panel. After each time the door closes, one of the buttons goes out. The final time the door opens the wall outside is orange, not brown, so it is clearly another floor.
So, it appears that Elisa couldn't get the elevator to work while she was on it. It was still strange that she immediately pushed so many buttons and that she hid in corner. Is it possible that she had been on the elevator just earlier and the elevator wouldn't work so she got on again and thought to press a bunch of buttons? Perhaps someone else's suggestion that the elevator could be controlled remotely (i.e. by building staff watching on camera?) is true.
All in all I still find her behavior strange. She is at the age the schizophrenia develops (or it could be another problem). Elisa is 21 and had been in first year university. This is a bit later than most young adults would start. Perhaps health problems kept her from entering university and then when she finally did the stress caused mental health problems to flare up. All pure speculation on my part!
Regarding the shorts/skirt....I see black basketball shorts rather than a skirt. When she steps out of the elevator you can see the gap between the legs.
Even if Elisa is experiencing mental health issues, surely someone would have seen her and reported it?? Or are there too many people with 'challenges' in the area, such that people have learned just to ignore it as it's not uncommon?
I hope Elisa is safe and she has not come in harms way!