In just two years, Alison Brettschneider’s womenswear boutique has grown from an online-only enterprise to brick-and-mortar locations in Connecticut, the Hamptons and the Meatpacking District. Joining an additional Upper East Side locale, this latest addition to the 25 Park empire is designed as a French boudoir, with sumptuous velvet curtains and sparkling chandeliers, and carries emerging and chic women’s clothing lines such as Gryphon and Hanii Y. Park Avenue princesses can cozy up to A.L.C. leather puffer jackets ($1,145) and Haute Hippie pom-pom fur vests ($1,450) during the day and get decked in Robin Brouillette bias-cut satin gowns ($2,395) for nighttime galas. Unique to the flagship, an enclosed by-appointment personal shopping parlor offers privacy to VIPs and celebrity clientele such as Kim Kardashian and Olivia Palermo.