Jonathan Anderson made his most consequential statement yet as Dior ’s creative director Wednesday night, staging the house’s Cruise 2027 collection at the Los Angeles County Museum of Art in a show that felt less like a runway presentation than a love letter to California mythology. Guests were seated in the LACMA courtyard among monolithic curving cement walls, streetlamps and vintage convertibles as the bassline from Air’s “Sexy Boy” ricocheted off hard concrete while convertible headlights washed over glitter-slicked gowns and metallic knits.  The setting — LACMA’s newly opened David Geffen Galleries, designed by Pritzker Prize–winning architect Peter Zumthor — was itself a declaration of intent, a collision of fashion , art and architecture that announced Anderson as a designer playing an entirely different game than his predecessors. The front row read like a Hollywood power grid.…