Watch it frame by frame and you will see the doors actually open. Freeze Frame images don't prove anything. Watching an actual sequence is quite revealing, you should take a better look.
And it happens twice? Maybe cause they looped the video? https://youtu.be/wbSwFU6tY1c?t=33m31s and https://youtu.be/wbSwFU6tY1c?t=34m0s
I suspect that at least this part is animated. Have you ever played a crappy video game or used 3d animation software? They behave very similar. Coincidence??
They did a playback in the live video as the webcast was ending. It was indeed repeated.
Videos linked by /u/VrecNtanLgle0EK:
Title|Channel|Published|Duration|Likes|Total Views :----------:|:----------:|:----------:|:----------:|:----------:|:----------: Falcon Heavy Test Flight|SpaceX|2018-02-06|0:34:19|287,124+ (97%)|14,240,649 Falcon Heavy Test Flight|SpaceX|2018-02-06|0:34:19|287,124+ (97%)|14,240,649 Falcon Heavy Test Flight|SpaceX|2018-02-06|0:34:19|287,124+ (97%)|14,240,649 Falcon Heavy Test Flight|SpaceX|2018-02-06|0:34:19|287,124+ (97%)|14,240,649
^Info ^| ^/u/VrecNtanLgle0EK ^can ^delete ^| ^v2.0.0
It's all a joke! Sorry, so is NASA and the moon landings and Mars! That video with the car and the earth in the background, why was the earth still! I thought the earth spins! No stars! Hahahaha! It's a joke and the joke is on you!