Now here's a RPPC curio. I bought this postcard, as I recall, for the intelligent and friendly smile of the dog, not for any visual quirkiness (other than that the image was a good enough example of the very trendy vernacular-photo-collecting category--"cast shadow of photographer unintentionally visible."
Looking at the image now I see it's a bit more complex: a double exposure of some sort. The woman (?) here is standing on a porch with her back to a rather sparse-looking landscape. One might surmise that the light-source, the sun, is coming from behind her, casting her in darkness. Yet the dog, who seems to be in front of her, is fully illuminated by the sunlight.
How the silhouette plus secondary outline of the woman came to pass is beyond me. Dog seems to be having fun, though.