Feeling overwhelmed? Need to simplify your life?

Even presidents feel that way. In a 2016 New York Times profile of Barack Obama, former White House chief of staff Rahm Emanuel revealed an inside joke that he shared with the president in moments when they faced a crushing number of options: They would run away to Hawaii and open a T-shirt shack that sold shirts of only one color (white) and one size (medium).

“During difficult White House meetings when no good decision seemed possible,” read the article,” Mr. Emanuel would sometimes turn to Mr. Obama and say, ‘White.’ Mr. Obama would in turn say, ‘Medium.’”

Brooklyn-based artist Emily Spivack read that last summer and couldn’t get it out of her mind. “I was so moved by the idea,” she says. She thought it was funny, escapist and very human: Although very few people understand the demands of the presidency, anyone could relate on some level to “decision-making fatigue.”

Thus was born the pop-up shop “Medium White Tee.”

Part art installation, part Obama tribute, part retail therapy, the shop opened last month in Hawaii as a four-week exhibit presented by the Honolulu Museum of Art. It’s in an indoor-outdoor mall where anyone passing by can browse, relax and find a temporary refuge from the outside world.

Spivack, 38, created a limited edition of 1,000 shirts and a mini-tropical oasis to display them in: blue walls, palm trees, beach chairs and one circular rack of white cotton shirts, all size M. All are completely plain, with a simple logo at the neck. Each shirt is tagged with an edition number. The price: $44, an homage to Obama, the 44th president, with proceeds going to two Hawaiian charities. Half of the shirts are reserved for the stand; the other half are available online.

Obama received shirt No. 1 as a gift from his half-sister, Maya Soetoro-Ng, who lives in Hawaii and attended the opening.

As an artist, Spivack is fascinated by the connection between what we wear and contemporary culture; her book “Worn Stories” is a collection of vignettes about people and pieces of clothing that have sentimental or special meaning for them.

The universality and simplicity of a plain white T-shirt immediately struck a chord, and the exhibit came together unusually fast. “I think it speaks to Obama’s legacy,” Spivack says. She started working on the project in July, found donors to underwrite the shirts and other materials, and got the Honolulu museum, which was eager to participate in an homage to the state’s native son, on board.

The shop opened on Jan. 11, the day after Obama gave his farewell speech to the nation, and was designed to run through the end of his term and the beginning of the new administration. Before the election, Spivack thought of the exhibit as Obama riding into the sunset. Now she think it represents a temporary break for him: “Okay, he’s got a month to relax — and then he’s got to get back to work,” she says.

Spivack spent the first week in Hawaii personally manning the shack, which allowed her to interact with everyone who came through. Some visitors were art lovers who had read about it, some wanted to talk politics, but many were just curious about what appeared to be a very odd store. “It was so much fun,” she says.

The former president has been invited to drop by and run the shop himself (no luck so far) but volunteers from all over the country have been flying in to work at the exhibit, which runs until Feb. 9.

With a week left to go, Spivack says about 425 of the limited-edition shirts have been sold. (She’s saving shirt No. 2 for Emanuel, and another for Joe Biden.) No one has really balked at the price. Most buyers see the shirts as a piece of art that they’ll frame or hang on the wall, but “they can absolutely be worn,” Spivack says.

Not that you could tell if you saw someone wearing it. But that’s Art for you.