NEW YORK • Do the rich and famous care about how they dress when they are in a supposedly informal setting?
Here is the evidence.
Mr Francois-Henri Pinault, chief executive of Kering, the French giant that owns Gucci, Saint Laurent and Brioni, wore a zip-up hoodie.
Mr Ron Meyer, vice-chairman of media behemoth NBCUniversal, wore a black cardigan and baggy black shorts.
Ms Sheryl Sandberg, chief operating officer of Facebook, put on skinny cargo pants and a cardigan the colour of dried mud.
These were some of the outfits modelled at that ultimate showcase of mogul leisure wear formally known as the Allen & Company Sun Valley Conference 2017 and more colloquially called "summer camp for billionaires".
It may have ended recently, but its style preferences will resonate throughout the rest of the season.
If you want to know how to dress down like a power player during the vacation period, there is no better case study, thanks to the distillation of entrepreneurs, executives and influencers brought together every July by the event's founder Herb Allen, the better to deal-make and elephant-bump in the rarefied altitudes of the Idaho aerie.
Officially, there is no dress code beyond "relaxed" though name tags are encouraged, along with the gift gear passed out to all attendees: navy or cherry red fleeces, hoodies, vests, polo shirts and baseball caps.
And while the "no press" policy means fewer images emerge from the event, enough snaps of schmoozing lords of the universe exiting their cars on arrival or taking the air between meetings get released to provide fairly good intelligence on how they define off-duty dress.
Apparently, when you have reached the top of the mountain - literal and professional - it is really about the smarts, not the suits. At least as far as the male attendees go.
The women seem less inclined to pretend they have not thought at all about what they pack.
See, for example, fashion designer Diane von Furstenberg in a perfectly twisted scarf and suede jacket one day, a coordinated navy number and matching trousers the next while General Motors chief executive Mary Barra wore a cropped black leather motorcycle jacket over a white T-shirt.
But it is the men, in their rejection of the tailored sartorial culture in which most of them spend their days (the tech crowd excepted), whose attire is the most instructive.
The predominant choices - either the gym clothes shoved in the bottom drawer and then pulled out to meet the personal trainer in the private gym look, or the "polo and baggy jeans on the back deck where no one can see you" style.
Indeed, the only branded area on the body was really the foot, where Nikes were impossible to obscure; and the bridge of the nose, where the luxurious eyewear Persols and Oliver Peoples rest.
But that was nothing compared with the extreme relaxers, most notably the tech crowd, for whom dressing down is a natural form of camouflage - obvious thanks to the fact that their T-shirts and jeans actually fit them. (They are the Silicon equivalent of the tailored suit.)
The best examples were perhaps Mr Nick Woodman, from camera tech firm GoPro in a faded black T-shirt with a playing-card bunny on the front, or Amazon boss Jeff Bezos in a black polo, sleeves straining around his biceps.
Indeed, aside from navy, there was a lot of black on display, including on film producer Harvey Weinstein, music streaming provider Spotify's chief executive Daniel Ek and Ms Barra - possibly as much as there is during fashion week.
Which is interesting. You can understand it. After all, this is not really "off-duty" at all - it is faux off-duty.
Family may come along for the fun, but attendees are still dressing for one another. To pretend otherwise is disingenuous. And that means that, to a certain extent, what they wear is being chosen to send a message and define an attitude.
That being: Who can seem secure enough in their position to look fully unguarded? To not need any of the armour of power - aides, clothes, lawyers or polished shoes. To expose their soft underbelly (or loose underbelly as the case may be), the better to appear open and uncalculated with their peers.
Of course, if lesser mortals adopted the same strategy, they might just look sloppy.
The truth is, when it comes to casual clothing, people are all as subject to the effects of peer pressure and herd instinct as they are when it comes to professional clothing. It is just at the opposite extreme.