There are no videos of me from my childhood days, because taping everything wasn't very popular where I live back in the 90's. I have tons of pictures though, because my old grandpa loved to snap photos so much that I started crying early whenever I saw the camera in fear of the flash.
Anyway, though I only have photos as a reference, I noticed a similar fact. On many photos I look very normal, I laugh, interact with people and do quite silly things, but there are some very few photos on which I give off an autistic impression. Sometimes when looking at a picture and when I can remember, I find myself thinking back to the day it was taken and remember that this photo was a good shot in a good moment in which I didn't do something that would be considered as autistic.