Balenciaga gave us the sack dress, the egg coat, the baby doll and the belief in fashion as a religion.

For museum donor Mary Carrington, that meant an architectural Comme des Garcons cage skirt dress with black ruffles; for donor Marsha Anderson, a poofy, black satin sack dress by Rabih Kayrouz; for donor Mindy Stearns, a floor-length dress, by a French designer, made of mesh and geometric mirrors.

One entitled “Performance,” meant to be evergreen, and defined by classic couture tropes — the sack dress, the cold-shoulder top — remixed and regurgitated in the everyday uniform of his borderless land.

Mr. Gvasalia played with the sack dress, sure, but it became a sack jacket: nipped in at the waist, with a portrait collar wrenched out at the clavicle to form peaks around the neck and pooched out at the shoulder blades, as if it had been caught in the act of being shrugged off.

Now, a quick word about that Zara sack dress.