Mademoiselle Finette wasa dancer from the Mabille dance hall, a "public park dancer," i.e. a loose woman: dancer, actress and prostitute. She was renowned for her ability to perform splits during her shows.
Here Nadar shows her in a completely different light: in a luxurious outfit of cashmere and lace, flaunting barely more skin than a bit at her wrist. She seems to be gazing at something in the distance. Her coquetterie is revelaed by nothing more than her beauty spot and the tempting "kiss curl."