While she’s tweaked some of the wall colours and reupholstered the sofas in the dark-walled library with its shelves of red leather photo albums (“My mother puts one together for me every Christmas”), the apartment remains pretty much as it was when Grange put it together with her, complete with a selection from her parents’ remarkable art collection. There’s a Rothko monograph on the coffee table in the lounge, and a real Rothko hanging on the wall a few feet away, right next to an Ed Ruscha. There are Ellsworth Kellys aplenty (including a picture of Jack and the Beanstalk that Kelly created for one of her sons as a birthday present), while the giant looping scrawls of Cy Twombly in the hallway face a similarly gargantuan 18th-century tapestry from an antique store in Paris beloved of Estée (her grandmother had a townhouse close by). They’re all art treasures of museum quality, “but if the building was on re and I could only grab one piece, I’d probably take the Yves Klein,” says Lauder, pointing at a canvas that’s a solid panel of International Klein Blue. “The colour is a part of my DNA and brand. It’s the sea and the sky. I love it.”

The only room that has no art in it is the master bedroom, which is serene and entirely silver grey, with richly carpeted floors and velvet walls that soundproof it from the roar of traffic and sirens of Park Avenue outside. “We had to be practical,” explains Lauder. “We live on the same block as a re station.” The only obvious decoration in the room is a spectacular antique orb crystal chandelier. Next door is Lauder’s dressing room, with the same Gracie wallpaper that her grandmother had at home, and a dressing table with a Murano glass mirror that she inherited from her. This is her retreat when she has insomnia. “I like to lie on the chaise lounge with my iPad and read. My grandmother used to have a chaise she was in love with. She wanted somewhere to relax after her hair had been done, without messing it up.”

The AERIN brand is, so its Manhattan marketing machine tells us, based on Lauder’s “signature, effortless style.” But how would its founder describe the ingredients of that style? What’s specific to the look of AERIN as well as Lauder? “I think we are beige, and gold, and chocolate,” she says. “It’s pretty and it’s luxurious. It’s pink and American. We don’t do head-to-toe black. It’s heritage with a twist and it’s storytelling, like our Christmas candle ‘Salzburg Spice,’ inspired by the time I lived in Austria for a year and a half while my father was an ambassador there.”

One thing that Lauder is tapping into, both at home and with her eponymous brand, is a sense of old-fashioned New York luxury. One can’t imagine her living anywhere other than the Upper East Side or the Hamptons (where she does, of course, have another home). It’s the same kind of style, perhaps, that Estée championed and fashioned her empire on the remnants of the American Gilded Age, refracted through a European sensibility of couture, Clignancourt, and pink and gold-dusted macarons. You can see it in the AERIN products, in the new wallpapers and jacquard and paisley textiles produced in collaboration with Lee Jofa; the swatches of cotton and linen-mix ‘Wessex’ bear a distressed damask motif inspired by fabric that was once in her grandmother’s home. You can also see it in the Park Avenue apartment, in the recurrent use of animal print textiles that upholster club chairs, cover tablecloths, and carpet hallways. “I’ve always loved leopard,” she says. “I like the consistent theme, but I also have three dogs and two teenage boys, and pattern hides things.” Practical as well as chic, see; again: smart. For Christmas, however, the zebra print tablecloth gets swapped for a red one before the family dines around the circular table, sitting on gold antique chairs. “I love a round table,” she says. “It’s great for conversation, and immediately makes people comfortable.”

Is she a cook as well as host or is she a real New Yorker, with the standard untouched kitchen hardware? “I’m not going to lie. I can cook breakfast, maybe steak for supper for three people. But I usually get a caterer. I like chicken curries, lamb chops, and pasta dishes. I love it when there’s a lot of dishes on the table and everyone helps themselves.”

When Lauder first saw this apartment, she’d just had her first son. “It immediately struck me as our family home,” she says. “It felt wonderful, warm, and inviting. My parents live in a very contemporary space, with no curtains. When I was growing up I always wanted drapes and cushions and a table covered with wonderful objects and bowls of candy. That wasn’t part of my parents’ sensibility.” It was, however, Estée’s. It imprinted on Lauder and she channels it today: “My grandmother was into style. She was traditional. There was always a table full of books, flowers, and a notepad with a pen in the guest bedroom. It was luxurious with attention to detail. And it seemed effortless.”