New Action Movie Star or Stink Diffuser?

At first glance, when My Honey brought this home the other day, I thought it was hairspray for fellas. Asked him if it was his and he said, "no", it's for his son, who's 11. The kid has pretty short hair, so that seemed surprising. Then I used my mad skills to actually read the can of "Motionsense Dry Spray", which is motion activated.

Hmm.

Could some of you science-y types please explain to me what goes into a pit spray that knows when you're "in motion"?

Thank you.