"I've seen a couple of them where he's double-fisting," said Steven Rea, author of Hollywood Cafe: Coffee With the Stars.

Fetching a simple cup often acts as a mysteriously humanising force for celebrities - "a common denominator," as Rea put it - because it's affordable and often part of a daily ritual. Sure, Taylor Swift reportedly bought a Rhode Island mansion for $17.75 million (A$22.57 million), but she grabs the same iced coffee we do. It wasn't always this way, though. Coffee used to do the opposite, acting as visual evidence that celebrities were way cooler than the rest of us.

Coffee has "always been a part of the fabric of the Hollywood scene" because of early-morning call times, according to Rea. His 192-page book, published in 2015, is filled with vintage photographs that feature actors drinking coffee on and off set. There are shots of Lauren Bacall and Humphrey Bogart making it at home with fancy gadgets, and others of Grace Kelly and Steve McQueen at the craft services table on movie sets.

"It became a Hollywood habit, mostly in good ways," he said. "If you're going to have an addiction, coffee is one where the downsides aren't that bad."

A steaming mug at a cafe offered what Rea called the "European sophistication factor." Hollywood has had ties to Europe from the silent era onward, when actors and filmmakers came from the continent's major cities and brought their coffee habits with them. Photos of Bacall drinking coffee with a cigarette between her fingers mirror similar ones of French actress Jeanne Moreau or Italian actress Sophia Loren.

"They brought with them their taste - the food they loved and the beverages they were used to drinking," Rea said.

Some Americans contributed to the development of this trend, too, adopting habits from their time abroad in the early 20th century. F. Scott Fitzgerald and Ernest Hemingway, for instance, spent time in Europe during their formative years, Rea said, and you can find photographs of each writer sitting in Parisian cafes. Both returned to the United States and worked in Hollywood, bringing back aspects of the coffee culture of Paris's literary and art circles.

But no longer. Purchasing brewed coffee became ubiquitous with the rise of second-wave coffee culture in the 1990s, according to Sarah Lyon, an associate professor of anthropology at the University of Kentucky. Going to Starbucks is a "middle-class luxury," something that many people can afford on a semi-regular basis. Affleck and Shookus' green straws are a mark of the everyman.

"I think it's a way for middle America to identify with the stars, through a small luxury, but not in this elitist way," Lyon said. "If he was going to some sort of elitist, third-wave coffee shop where they were having their $5 pour-over coffee, people wouldn't identify and react in the same way."

Lyon specified that it's the act of grabbing the drink themselves that humanises the celebrities, who could easily staff it out.

"It's something about the ritual of going to the store and carrying the coffee around in a paper cup," she said. "It's just a caffeine delivery mechanism - there's nothing much to it, in and of itself. It's the consumption, the publicness of it."

Jerry Seinfeld's Emmy-nominated web series Comedians in Cars Getting Coffee plays off this idea by, as the name suggests, having Seinfeld drive his guest across town to get a cup. The series serves the same purpose as any talk show, but the premise allows for more relaxed conversations. Seinfeld sometimes deviates from the structure, running into other people en route, and the public setting makes the comedians appear more humble. Stand-ups often thrive on relatability during comedy routines, after all, and the departure from a traditional studio setting achieves a similar effect.

So, why coffee?

When asked by NPR why he chose coffee, Seinfeld replied, "That whole description of why it's great to meet someone for a cup of coffee - the ease, the simplicity, the compactness. And that it also obviously gets people talking. You have coffee, and, for some reason, it makes you talk a lot."

The Washington Post