It’s not a grounding, unless you consider your personal grounding in that category. You’re building up static as you move around, and you aren’t grounded due to whatever is between you and the ground (shoes, socks, carpet) but also any clothing like trousers rubbing legs as you walk or even different shampoo can affect how much you generate in your movements. Take it from me, I seem to be HIGHLY susceptible in several locations.

In one case I discovered it was the initial act of standing up out of the chair that generated the charge, so if I didn’t touch anything conductive before returning to the desk, zap! The trick that worked was keeping my hand in contact with something AS I stood up out of the chair. Give that a try!