Too many different angles showing the same thing, too many Youtube videos popping up for it to be a video loop job. It was real. She had some sort of a seizure.
From someone who suffered seizures from a head injury as a child.......that was not a seizure. If it had been a grand mal seizure she would have lost consciousness and needed medical attention.
Could be something neurological where it affects the muscles in her neck.
The blinking eyes could be indicative of some petty mal seizures.