The house is early 20th century, Mies Van der Rohe inspired, and black Le Corbusier leather chairs match the architecture of the time; but the costumes (by Yan Tax) vary between period and contemporary ones. The program notes detail how the set underscores the relationships between the different protagonists, but we found this interpretation a bit too subtle for the camp, over-the-top, no-holds-barred stage direction of Roy Rallo.
Pictures courtesy of SF Opera/Terrence McCarthy. Above, the set; below, John Osborn.