What Grace is suggesting here is that Tedd intentionally use stimming to help pay attention.
I don't feel qualified to explain it well, but I've heard it described as an outlet for excess mental energy, and it's my understanding is that it's what things like "fidget spinners" were intended to help with.
My understanding is it's common, if not the norm, for people with ADHD, or in the Autism Spectrum.
It's also something I do a LOT. I don't know how many calories I burned just from moving my legs while making this very page, but I assume it's not insignificant.
It's something done as far back as I can remember, and well before I had any idea what the heck I was doing.
I have trouble standing still. If I'm not sitting, I MUCH prefer to pace.
If I have to remain in one spot, and I don't have something like a phone to distract me, I'll balance on one leg. Or I'll check the phone, AND balance on one leg.
Most mysterious for me before getting some sort of explanation for it was tapping out musical beats, and taking a while to even realize I was doing it. Most common was the theme for "The Veldt" from Final Fantasy VI.
So, yeah. I was mysteriously tapping out video game beats without consciously meaning to as a teenager, which was a LITTLE confusing. Nice to have some idea what's up with that now.
And that's just a few examples. I have more. It's possible sketching while in school counted. I paid better attention when I drew in class, though many teachers immediately assumed the opposite was happening.
ANYWAY! If you're like me, this can be helpful for paying attention in social situations if it can be done without being disruptive, and I've used it to avoid impulsively checking my phone while trying to focus on other things.
Tapping the pocket containing my phone rather than actually looking at my phone has successfully kept me focused, and not impulsively wanting to check it, before (though it's also failed).
I've rambled a bit, but that happens when I get on personal topics like these.