They gossip. They touch. They sit cross-legged. And in today's slice-of-life store window settings you see them in bathrooms, barns and ballrooms, dancing, climbing ladders, doing everything people do.

And that's precisely the point.

Adel Rootstein's mannequins are so true-to-life that they mirror the movement as well as the look of their living models - "frozen moments," Rootstein calls them - and they have demolished the isolated, doll-like look and static style and stance of mannequins that preceded them.

The current favorite is Sayoko, leading Japanese model who was star of the most recent Paris fashion shows. She's the hit of the latest of Rootstein's twice yearly collections of virtually handmade and handpainted fiberglass mannequins used by Henri Bendel, Woodward & Lothrop, Hecht's, Bloomingdale's, Saks and Lord & Taylor, among others.

Rootstein's firm produces about 9,000 a year now, weighing 20 pounds and costing $495 on arrival in New York.

"You can put rags on them," says Robert Rufino, who's in charge of visual planning for Bendel's, "and they make the clothes look super."

In 1961, when Rootstein arrived in London from South Africa to work as a window dresser, store mannequins were picture-book-pretty dummies with 17-inch waists, 33-or 34-inch bosoms, stick legs and obvious metal fittings keeping them together. Most were French or Danish made, and new versions were offered every eight years, with little change from the style shown previously. But the presentation of the new mannequins was always a major event.

Rootstein's revolutionary concept - designing mannequins in the image of real people in natural poses, including sitting and lying down, seemed so natural she had no idea no one else was doing it.

"Magazines had begun to relate clothes to real people, yet it never occurred to stores to do this with their window displays, even though this is precisely what they were selling," said Rootstein recently in her showroom just off Kings Road.

At the start, all her mannequins were size 10 and 5-feet-9 or 10, the standard of fashion models at the time.

But Twiggy changed all that. She was size 6, 5-feet-4 "with no tits and bow legs," Rootstein recalls. Twiggy, she says, gave her carte blanche to inflate her bosom.

What's more, "Twiggy never stood erect and no mannequin has stood erect since," Rootstein observed.

Mannequis were endowed with nipples and navels in the late 1960s as women's clothing became more explicit - with bralessness and clingy and see-through fabrics. Metal fittings were changed to accommodate bikini bathing suits.

In 1974, Rootstein added a collection of fat ladies she called "Pretty & Plump." There are fat people in this world and they ought to wear clothes for fat people, shown on fat models and mannequins, not those stuffed with pillows," said Rootstein, irritated that some shops even scale display garments for stout women to a more typical model size. ("That should be against the fair description act or something," Rootstein says angrily.)

"Fat people are usually called anything except fat or big and plump which I think is a great pity," says Rootstein, who is 5-feet-2, dark haired and trim, "because people should be accepted for what they are and should dress for what they are."

In the same year she tapped Twiggy, Rootstein made the first black mannequin anyone in the industry can recall. Until then stores had been using suntanned figures but no black mannequins existed. Rootstein chose New York model Donyale Luna "because she was fabulous, not for any political reason at all." A New Orleans store, D. H. Holmes, was the first to display "Luna" while other stores packed her away for future use.

But it was not until after the riots of the late '60s that store windows were integrated. Out came Luna who, according to Rootstein, was still the only black mannequin available.

Rootstein herself chooses the concept and poses for each of the twice yearly collections of mannequins. A new "model" is photographed and interviewed for several days - "We go out together and look at her all the time," she says. "The model brings her character to the work, the sculptor, John Taylor, his ability."

Makeup is applied to mannequins in a theatrical way. "When one makes them humanly realistic, as opposed to theatrically realistic, it gets kind of a dead quality," says Rootstein. "This has got to be a moving, living thing, although it stands still, so it has to be theatrical." Makeup is geared to the viewer standing seven feet from the figure - the average distance from outside the store window.

Rufino at Bendel's finds the painted mannequins too "done up" so he orders his with a fresh scrubbed, unpainted look and then applies real makeup, changing it each week.

Wigs are made by hand from scratch, but while the particular style the model wears is made, it is only one of an assortment shown with the mannequins. Currently in the Chelsea showroom, Farrah Fawcett-Majors wigs endow many of the mannequins' bald heads. Rootstein would like to "do" Majors - "It's a joy to see someone that is truly beautiful," but hasn't yet approached her. Other considerations are Margaux Hemingway and New York model Billie Blair.

Few current front page personalities give Rootstein what she calls a "fashion feeling" to inspire their use as models. Margaret Trudeau doesn't have it. Neither does Jackie Onassis. Lee Radziwill does, but she consented to model just before the assassination of Robert Kennedy, and later Rootstein never pursued the idea.

As for the punk kids in her neighborhood with whom Rootstein sympathizes, they are not likely candidates either. "I'd only have to add some frizzy colored hair and have the basis of the look," she says.

Sighs Rootstein, "It is time for a revival of really beautiful woman."