Harlow poses with her hands on her hips (1). This maillot even has a name (2).
This widely-distributed image appears in many contempory sources. The maillot is tight-fitting, still has shoulder straps, a tiny leg, and completely bares the underarm. See especially the relationships with the maillots in early 1930s.
From Daniel Blum, A Pictorial History of the Talkies, Grosset & Dunlap, New York, 1958. This is coincidental with her movie Reckless in 1935. 2 pictures.