Clockwise from top left: Donald Trump with Ivana in 1988; a scene from “American Psycho” on Broadway; an ’80s look from Hedi Slimane’s last collection for Saint Laurent in 2016; Barneys, back on Seventh Avenue after years away; Cyndi Lauper in her ’80s heyday; and Molly Prentiss’s debut novel, about the SoHo art scene in 1980.