People are flashing so much skin at the office this summer that you’d think they were headed to a barbecue or the beach.

The scandalized among us tend to focus on a few notable clothing items, like “corporate” crop tops on women and shorts on men . But it isn’t just a midriff here and a hairy thigh there making workplaces especially fleshy this season. It’s the combination of several recent fashion trends , from micro skirts to crocheted shirts, that leave less to the imagination.

Conventional wisdom is that desk workers forgot, or never learned, how to dress for the office during the pandemic. That’s a stale, patronizing explanation. People know what they’re doing.

The real folly is companies’ ambiguous or nonexistent guidance on what is OK to wear. Just 57% of workers recently surveyed by Monster.com said they had worked in an office with a dress code—any dress code—in the past year.

When has leaving things up to people’s sense of good taste worked out well?

Remember that we were subjected to bare calves and wide-open shirt buttons in the U.S. Senate chamber when lawmakers briefly relaxed their wardrobe rules a couple of years ago. They reinstituted a business-wear policy when Sen. John Fetterman proved common sense is rarer than you might think.

Companies desperate to avoid being seen as stuffy have effectively told employees to set their own standards. Thanks to the cool bosses of America, we’re now scoping each other’s tan lines and learning more than we care to know about co-workers’ sunscreen habits.

Flaunt it

Ruth Zwieg, a sales executive in Florida, advises the younger colleagues she mentors against cleavage and spandex. Fair or not, they will be taken more seriously if they project smarts before sex appeal, she reasons.

She recently got some advice of her own when she ran into a 20-something professional acquaintance in a barre and Pilates class: “She said, ‘Oh my God, Ruth, you’re in such great shape. You should show more of your body.’”

Zwieg, 63, doesn’t aspire to be the “office siren.” (If you’re not up on this meme, type the phrase into TikTok or Instagram and you’ll get the idea.) She sees her conservative approach to professional attire being replaced by the idea that if you’ve got it, flaunt it.

“And now with Ozempic and everyone losing enormous amounts of weight , I see men and women becoming more daring with what they wear because they want to show off this new body,” she says.

Call it a natural—not quite au naturel —result of boosted confidence meeting lax rules.

I’d say stare at the floor if you’re blushing, but even there you’re liable to glimpse sandals and open-toed shoes, assuming your co-workers wear shoes at all. Rachel Nazhand, a 36-year-old software vice president in Washington, D.C., has worked with engineers who parade around the office barefoot.

“They said it was easier for them to think,” she says.

Showing our full selves at work is supposed to be a figure of speech about authentic personalities. Clearly some are taking the phrase a little too literally.

Bare maximum

I strolled through downtown Boston at lunchtime the other day, as people ventured out of air-conditioned offices into 80-plus degrees on their way to Sweetgreen and other bowl places. Like much of the country, the city has been trapped under a “ heat dome ” this summer.

If not for corporate badges on lanyards, it would have been impossible to tell many professionals apart from the tourists in tank tops and flip-flops.

Several vented their disapproval of colleagues’ wardrobe choices when I stopped them on the street.

“Younger people get all their information about everything from crazy people on the internet, and you’ve got crazy people showing up half-naked and thinking that’s the norm,” said Jane Papa, 79.

Maybe it was the heat, but her judgment started to melt as she recalled women at her first job in the ’70s having their skirt lengths measured. Better for dress codes to be too loose than too strict, she decided.

Plus, Papa conceded, some finger-waggers may be jealous of those who can pull off more revealing styles.

“I mean, I would wear those things too if I could,” she said, laughing.

Still, the young and the flabless don’t all agree that baring more is a good idea.

“I prefer that people dress very modestly in the office,” 30-year-old Dorian Selimi told me as he sat at a table in the shade, sporting slacks and an Oxford. “You go there to work; you don’t go there to show off.”

Seeking an expert’s take, I strode to an upscale clothing store where an associate named Michael handed me a chilled bottle of Acqua Panna and complimented my Johnny collar polo . A black A-shirt peeked out beneath his short-sleeve button-down.

His look seemed perfetto when I raised the subject of summer office attire and he responded with an oft-quoted line from “The Sopranos”: “ A don doesn’t wear shorts. ”

Maybe our workplaces should be more like the mafia, at least when it comes to dress codes.

Write to Callum Borchers at callum.borchers@wsj.com