I notice throughout the movie Carrie seems to tremble a lot, anybody else notice this? I just wanted to know if it was intentional? In the scene when she was in the classroom while the teacher was talking she looked like she was having a seizure.
My interpretation is that she was concentrating so hard and expending so much energy that it caused her to shake. Kind of like how people shake when they get really angry.
I think the classroom episode WAS a seizure. She was so upset that her TK took over and she went into a trance (although not to the extent that she was at prom). Also, later, at the bowling alley, Chris says to Sue, "remember when she had that seizure in 1st grade and told everyone she was speaking in tongues." The same thing happened back in 1st grade, but she didn't know what was going on or how to explain it, so she just said she was speaking in tongues.
But... a seizure and a trance are two different things, although they can appear similar. I've imagined a resolution to this in a fanfiction sequel I wrote to this particular version of Carrie... if you're interested, PM me.
The writer and director had a slightly different take on Carrie's mental status and movements than what King described in the book. She's fixated and also emotionally dissociated - not really in control of herself during the episode, so she's standing very still or walking stiffly. But if you look closely you'll see her shake and move with some effort.
2. Her powers are beginning to manifest and she's using all her energy either to bring them forward- or perhaps it takes all her energy to hold them back considering all the damage she does without really breaking a sweat.