It's obvious, mainly from the portion of an automobile in view, that this is a photograph taken towards the end of the 30s. And the lady certainly has the mid- to late-Thirties look to her. But the outfit that she is wearing is notable because, 1. it is a two-piece, with a bare midriff, 2. it is obviously NOT lingerie, 3. but it is hard to believe it is a swimsuit, since two-piece suits were still at least a decade away.
Something rather bizarre appears to be happening at hip level. It almost looks like the lady has inserted a gas pump spigot into her outfit bottom, at the same time distorting the lines of her lower torso. Or, that, perhaps her outfit bottom has slipped to reveal a slice of her upper rump.
Whatever the case, the attractive girl's facial expression is very sexy and come-hither. A very interesting picture, overall.