His name might not be very familiar, but the works of graphic artist Milton Glaser — whose prolific output includes the “I Love NY” ad campaign, as well as album covers for Townes Van Zandt and Nina Simone — are recognizable to many. Revisiting the famed paintings, drawings, logos, prints, posters and other works by Glaser, filmmaker Wendy Keys creates a rich and engaging mosaic of a key figure in American iconography.