I'm not sure

It's definately faster then real life, speed up.
My guess:
Looks like a time-lapse made of long exposure shots, and multiple copies of this time-lapse video layered for frameblending (so you're not looking at one photo at the time but probably 10 or 50 ?).
Although I would expect the letters to fade away one by one during the take, but the letters stay visible the whole take...