When a pop star memorializes their world tour as a movie, trust: the red carpet premiere will be as fashion-forward as the first show. In 2023, Beyoncé wore Balmain, Alaïa, Versace, and custom Thom Browne for Renaissance screenings; Taylor Swift watched The Eras Tour film in a five-figure Oscar de la Renta gown. Today, Billie Eilish celebrated her Hit Me Hard and Soft: The Tour film in a Celine take on the ballet sneaker trend , which would've looked so sleek on stage. Before the "live in 3D" tour hits theaters on May 8, Eilish celebrated the UK premiere in head-to-toe Celine . Stylist Spencer Singer chose an extra-oversize suit which felt true to Eilish's signature style. But Singer's most Eilish-coded select was undeniably Celine's $900 Flat Sneaker. Billie Eilish arrived at the Hit Me Hard and Soft: The Tour premiere in ballet sneakers from Celine.…