David Geffen famously shuns interviews, so his Instagram account — which the mogul-philanthropist launched in 2016 — offers the only window into his private world. And what a view.

That's thanks in large part — 138 meters, to be exact — to Rising Sun, the superyacht he purchased in 2010 from fellow billionaire Larry Ellison, on which Geffen hosts some of the world's most famous names from film, music, business and politics. With many of those guests smiling in photos against the backdrop of Ibiza, Mallorca or Capri for his 72,000 followers, poring over Geffen's Insta has become a Hollywood pastime. C-suites were abuzz with this summer's guest log: Oprah Winfrey, Gayle King, Katy Perry with fiance Orlando Bloom, Chris Rock with girlfriend Megalyn Echikunwoke, Karlie Kloss and husband Josh Kushner (brother of Jared), Goldman Sachs' Lloyd Blankfein and wife Laura, K5 Global founder Michael Kives and wife Lydia (a nonprofit attorney), oil heir Mikey Hess and designer fiancee Misha Nonoo.

But the yachty who inspired the most chatter was the world's richest man, Jeff Bezos, posted Aug. 6 in a group shot with girlfriend Lauren Sanchez-Whitesell. Bezos, seen barefoot and in board shorts clutching a wine glass, has his own Instagram but never gives his 987,000 followers a glimpse at his private world. So appearing on Geffen's, especially in the same photo as Sanchez-Whitesell, could seem like the ultimate flex for his host. But sources familiar with Rising Sun activities say Geffen, 76, is not strategic about the shots he posts.

"He's just at the place in his life where he doesn't care," offers one. Says another well-placed industry source: "There's a reason the most powerful people in the world show up. It is the most coveted, most exclusive and most unbelievable vacation experience ever."

Since Geffen has been documenting his guests, he's snapped Disney's Bob Iger, Steven Spielberg, J.J. Abrams, NBCUniversal's Ron Meyer, Netflix's Ted Sarandos, Julia Roberts, Leonardo DiCaprio, Barry Diller and wife Diane von Furstenberg, Bruce Springsteen, Paul McCartney, Tom Hanks and Rita Wilson, Jerry Seinfeld, Diane Sawyer, Scooter Braun, Bradley Cooper, Mariah Carey, film executive Stacey Snider, and producers Walter Parkes and Laurie MacDonald. One couple he hosted but never posted: Barack and Michelle Obama.

By all accounts, his guests are smitten. "You are the most gracious host," wrote Bloom to Geffen in the comments section underneath a photo of the pair. Kloss, who, like Kives and the Blankfeins, is a Rising Sun regular, once wrote "the most magnificent weekend with the most extraordinary man," after an excursion. 

There’s a reason that many of the images Geffen posts look similar, posted from the deck or common dining areas. According to yacht expert Nick Jeffery of Nick Jeffery Yacht Publicity in Monaco, common etiquette is to photograph and post exterior shots only. If the inside quarters are ever photographed, it's typically done by professionals in carefully curated photo shoots to protect expensive artwork and furniture. 

Jeffery suggests that Bezos, who is known to travel with his own personal security team, must have granted his permission for Geffen to post the photo, one that Jeffery says contains one glaring problem. "The photographer should have removed or topped up his glass!"

Perry and others also have posted (or reposted Geffen's shots) on their Instas. An individual with knowledge of both Hollywood and yachting etiquette says guests should pause before pulling out a smartphone. "You can do a dry run test by taking your phone out to pretend to check a message. If you see the boat owner get antsy or look your way, put it right back. … After all, the yacht is their sanctuary."

Rising Sun may be his sanctuary, but Geffen remains rooted to his upbringing, says author Kevin Sessums, who knows him. "For someone who is very rich and very famous he also has always been the boy from Brooklyn with his nose pressed against the window. Instagram is just a newfangled window," says Sessums. "That's why I've always loved him. For all the trappings of an elite life, he's still pretty egalitarian regarding his outlook on life itself. He's a mensch."

One publicist whose client has been photographed on Rising Sun says that while A-listers value discretion, there's not much of a downside to appearing in Geffen's feed. "It's a glamorous, mega-millions yacht and his groups are always the best, so you'd be hard-pressed to find somebody who is like, 'Nah, I'm good, I don't need my picture taken,' " says the rep. "It's a status thing. When Paul Allen used to have big parties in Cannes on his yacht, people would try to pay money to get on the boat because if you're seen there, it would be worth something. Same for David Geffen."

But good luck scoring an invite. "There's no way to catapult into that world without already being in that world," explains the rep. "If you have fame, great. If you have money, great. But otherwise there's no chance."

A version of this story first appeared in the Aug. 21 issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.