Won Hundred black mini cocktail dress

Interesting shape, smooth satiny material. By Danish brand WH 100 by Won Hundred. Keyhole cutout in back. Purchased at a consignment store in Brooklyn a few years ago. One belt loop is half off, I fixed with a pin (see photo). Didn’t come with a belt. Has pockets. Unlined but material is thick. No care tag, my guess is polyester.