A graphic, black-and-white Brick Throw by Sylvain Willenz for Hem sits atop a Form Us With Love sofa, also for Hem. The silver hemisphere — which visitors to the apartment often mistake for an art object, is actually a giant dome Mattan picked up from Canal Street Plastics. The splatter-painted stool is by Max Lamb, and the white stool is by Hallgeir Homstvedt, both for Hem. The red, vintage Swiss Air book is a nod to Mattan’s aeronautics obsession.