After a four-year renovation, the doors of Tiffany & Co.’s Fifth Avenue new The Landmark flagship opened wide on Thursday, April 27, to welcome A-listers in celebration of the institution’s return. Anya Taylor-Joy, Hailey Bieber, and more chose looks that would best highlight the real stars of the night—the jewels—as they danced the night away to Katy Perry and Mark Ronson.