A pizza is what you see on the floor after severe nausea when you feel ill, so you puke and throw up.
Your guts content comes from the acid stomach up and through your mouth and falls down on the floor or ground.
Even if your not intoxicated it will look like a pizza when you puke and "lay a pizza".
The effect might not be calmed down by ordering a real take away pizza the minute after, to fill the stomach.
buddy 1 "I felt soo bad after that hamburger so I layed several pizzas!!!!"
buddy 2 "Lets go and order some baked pizzas then so you feel better dude!!!"