The staff at The Fifth Avenue Spa showers clients with a repertoire of soothing treatments amid white leather couches and swaying sprays of cut flowers. Décor characterized by shades of sand lets accents of purple leap from sunset photographs, blooming orchids, and images of flying people-eaters gracing the walls. With contented sighs drifting free after massages and body wraps, patrons shutter electronic devices so as not to break the relaxing spell. The intimately lit treatment rooms make eyelids increasingly heavy and delight off-leash shadow puppets during waxing treatments and facials.