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.