NEW YORK — You don’t walk into C.O. Bigelow, a 187-year-old apothecary in downtown Manhattan’s Greenwich Village, for the same reasons you might walk into another neighborhood pharmacy chain.

Lovers of the “quiet luxury” trend and the ‘90s nostalgia rejoice—an astute TikToker has now discovered that eternal fashion icon Carolyn Bessette-Kennedy’s exact headbands are still ...