I'll start the boring part by suggesting that the body shape and behavior are consistent with a caterpillar of an underwing moth (probably catocala spp.)
Your last sentence is quite insightful. There is a vast difference between having a pleasure available whenever desired with a few clicks, versus having to wait until a certain time and if missed it was apparently gone forever.
Drawing a clock face is still a component of mini-mental-status exams in tests of cognitive impairment such as the Saint Louis University Mental Status Exam. I have wondered whether this component needs to be modified.
If you're going to do this properly, you should wrap just half your teeth and leave the other half untreated as a control for comparison. We'd like to see that followup photo.
That can't be the explanation, because this isn't a "magic" competition - it's an optical illusion competition, so sleight-of-hand etc is forbidden. Entrants in this competition rely only on the neurophysiology of vision to generate the illusions.
At the risk of expressing a "get off my lawn" sentiment, I find it distressing that someone would prey on the goodwill of strangers for his own self-aggrandizement.
Very interesting, especially considering that beer, unlike water, contains plenty of nutrients capable of supporting the growth of bacteria and fungi. I would be reluctant to drink beer from a public fountain.
http://aging.slu.edu/index.php?page=saint-louis-university-mental-status-slums-exam
https://www.youtube.com/watch?v=SKpOKXAVjGo