Last year the California-based retailer opened a mammoth prototype store near Buckhead Atlanta. Its six stories, connected by curved double staircases, feature a Ben Soleimani Rugs showroom, an interior design center, furnishings for “small spaces,” and RH Baby & Child. Twelve-foot glass doors open onto Juliet balconies and terraces, and an 8,000-square-foot rooftop “conservatory” crowns the megamansion.