“You’re the top,” wrote Cole Porter in a song from Anything Goes, “You’re an Arrow collar.” One suspects that Porter, who though married was homosexual, was thinking less of the collar and more of the Arrow Collar Man, as drawn in the famous ads by artist and illustrator J. C. Leyendecker. Born in 1874 in Montabaur, Germany, Joseph Christian Leyendecker came to America at eight when his family immigrated to Chicago. He studied at the Chicago Art Institute and spent a year at the Académie Julian in Paris. Returning home, he received a commission for the cover of Saturday Evening Post, a work relationship that would last 44 years. With the turn of the century came the Arrow commission. The male counterpart of the Gibson Girl (created by Charles Dana Gibson), Leyendecker’s Arrow Collar Man was a Wasp paragon with a crisp profile and perfect proportions. “Under Cover” revisits the work of this influential illustrator, who died in 1951, and explores the homoerotic undertones in his visions of masculine beauty. —L.J.