This is a rare metaphysical French postcard using the anatomy of the face to tell certain things about a person. On the back side, it is dated Monday, May 6, 1918. The design is eye-catching! As best as Google and I can decipher, the French text says under the 'explanation of the signs': Anatomical and physiological research shows that birth signs on the face are always repeated on a specific part of the body. And by examining the place of one of the 20 signs marked in this figure, then looking at the table below, you will positively see on what body part this sign is repeated and we can say that this lady in the figure above, whatever her birth sign, must have the same sign in the arm, breast, etc. So for example, the Number 12 under the woman's chin on her neck relates to her buttocks (a la fesse). No. 18 by her ear relates to the leg.
To be honest, none of this makes sense to me because I'm not familiar with this form of fortune telling. I thought at first it might relate to acupuncture points but the French text specifically mentions birth signs, so this is what makes me think it has to do with astrology, which does assign certain body parts to be ruled by a particular sign.
Anyway, I hope you will buy the card based on what you know, see here and like; not on my uncertain translation:) As I mentioned from the onset, however, I feel confident in saying this is a rare card (I've never seen it before!) The heart of the image is incredibly preserved, all the more so considering its light color. However, the outside edge shows wear and soiling. Not enough to be detracting but to verify its (almost) antiquity. No creases. Size: about 3.5 by 5.25.