I cannot say to love this artist, I don't like his heavy monumentalism of Cubist origin so widespread in Europe in the years between the two wars. I find it ambiguous and a little hypocrit. But this portrait of naked man is special. As someone rightly pointed out this is a portrait of the sexual desire. The black thong has its motives in the moralism of the time, it could not even be there and show the genitals, it would not change anything. It is powerful and highly attractive. Hartley was in his sixties, at the age when you abandon yourself to desires, in that age when you are desperate but the desire for beauty is stronger than ever.