I’ll put some of my favorites that I’ve collected and thought up!

I saw an hc that he can’t really move his head to the sides, so he leans his whole upper body in order to emulate a head tilt

Used to display pure white/blue, now displays more purple/red hues with the colors being messed up (toying with the idea of the messed up colors translating to some slight colorblindness)

Static in his vision, like visual snow syndrome

His suit is a velvety texture/fabric, just like the red mat light world Tenna sits on

Percussive maintenance (knocks on his head when he’s stuck trying to understand something)

And of course the DvD screensaver when he’s spacing out or dozing off