A solitary figure, microphone and stool. Those are the primary images of stand-up comedy, reliable and ubiquitous as a book's cover, spine and chapter titles. There is maybe one other element in the iconography, and it's the most revealing: The water bottle.
Once you start looking for drinks in stand-up specials, they're everywhere, photobombing stars, perched in corners, upstaging, hiding, as upright and alone as the comic. Their purpose seems obvious — to quench thirst, duh — but then again, stage actors get dry mouths and no Hamlet puts down his sword to pick up an Evian. The water bottle is the prop that clues us in that a comic — not a character — is at work. The drink seems blandly functional, but it gets more interesting once you realise that it's also a choice.
You can tell a lot about a comedian from their water vessel. Take Jerry Seinfeld, a renowned perfectionist whose jokes display polish, control and refinement. In his recent special 23 Hours to Kill, he places an elegant glass next to a sleek label-less bottle of water with a flat top. If it looks like something James Bond might drink, the white goblet that Katt Williams uses in The Pimp Chronicles Pt. 1 (2006) belongs more to the Knights of the Round Table, emphasising his regal levels of eccentricity and flamboyance.
While actors can dash away for a drink at intermission, comedy doesn't hide the rest and recuperation. Why? Convenience? Tradition? It may be that stand-up traditionally leans so much on authenticity; the idea that the comic onstage is telling you what they think, not just playing a character and refining ideas into constructions designed to make you laugh. The glass of water telegraphs that you are watching a human at work, sweating. It adds to the realism.
Size (and quantity) matter. Ali Wong uses a stylish, extra tall bottle, and Hasan Minhaj puts two bottles of water on top of the stool, both working in a tradition but offering just enough variation to look distinct. No one was more prepared than Robin Williams, who had a battalion of bottles near him in Live on Broadway (2002), a preposterous if necessary amount of hydration that emphasised the amount of energy the frenetic comic expended in a typical show — while also being its own sight gag.