I’m guessing because it’s that many cans he was holding the cans upright and sniffing the gas propellant. I’d see it a lot at the grocery store that I worked at in college - lots of full whipped cream cans with the tops off - apparently they get some kind of high off of it.
Yep, called a “whip it” nitrous oxide.
It’s why you see the cans wrapped in cellophane now.