From Philadelphia Museum of Art:
In August 1928, Picasso and his family vacationed at Dinard, a popular resort town on the northwestern coast of France. During this vacation, the artist completed a series of paintings of naked female bathers playing with beach balls as studies for a never-realized monument. Although his wife, Olga, accompanied Picasso on this trip, the grotesque female figures that appear in these works are thought to represent his teenage mistress, Marie-Thérèse Walter, who secretly lodged nearby. Walter's body has been transformed in this painting into a strange anthropomorphic structure, with a button head, boomerang-shaped torso, conelike breasts, and tubular sticks for limbs.