He was just playing up his Tourette's for the videos.
There are a lot of cases of Tourette's where it'll just be one or two tics that most people don't notice in casual life.
I knew a guy in college who had Tourette's and the only thing he'd do is make this "mmm-HMM" sound and wiggle his fingers a little bit.
AND GREW SO INCREDIBLY THIN
THAT EVEN THE END OF AN EYEDROPPER
SUCKED. HIM. IN.
NOW SKINNY NEVER KNEW ANY QUESTIONS
AND SKINNY NEVER LOOKED AT LIGHTS
BUT SKINNY SOLD SOMETHIN'
EVERY SINGLE NIGHT