NEW YORK — Inside Tribeca’s vintage Square Diner, with its midcentury patina and aroma of overheated coffee, about a dozen models are not so much posing as loitering. They are munching on french fries as they perch on red vinyl banquettes. Their eyes are heavily lined, and their hair has been teased into 1950s bouffants or roller-set into exaggerated curls.

And they are wearing dresses from Batsheva, the label designed by Batsheva Hay, a former lawyer who has a love for prairie dresses and buttoned-up ruffly blouses in old-fashioned cotton. Her business began two years ago as a passion project and has turned into a hot topic. And she is now a finalist in the CFDA-Vogue Fashion Fund competition.

So do not pooh-pooh prairie dresses.

The fashion industry has gotten behind them, and the modest, old-fashioned sensibility has had an influence far beyond their current popularity, which appears to be rising.

There’s a ripple of reserved femininity running through fashion. Young women have been drawn to dresses with small-scale floral prints, puffy sleeves and poofy shoulders. Hay’s vision has been the most pure. It doesn’t have the pop culture edginess of Gucci or the accessibility of Coach. Her clothes are far more earnest.

For spring 2019, her intent is to explore the inherent tension in the style that she is proposing. Her work has a retro sensibility, but she uses contemporary fabrics, such as pink and green metallics. One can most easily envision these dresses out in the country, but they are meant for city dwellers — they were, after all, designed by a woman who grew up in Queens. They are modest, in that they are high-necked and reveal little skin; but they are so out of the ordinary and visually jarring that they immediately draw attention to themselves and whomever happens to be wearing them.

There is something intriguing about what Hay is proposing, which is to use fashion as a visually symbolic rejection of the slickness of contemporary life. This is her answer to streetwear, which allows one to move incognito through the public square. The only connections are with like-minded passersby who understand the codes of prestige written into a particular sweatshirt or pair of sneakers. Batsheva eschews anonymity. There’s no hiding in these clothes.

They are provocative but only because they are so darned civil and precious and sweet. They don’t swagger. They don’t brag.

Their power is in everything that they refuse to be.