Long thought to be by famed French satirist, Honoré Daumier, it is now believed that this watercolour sketch is by some other 19th century hand.
Despite what appears to be a genuine set of the master's initials in the lower right, the obvious sexual nature of the subject places this sketch outside Daumier's oeuvre. In addition, most other details are not quite right; the even handling of the light is not typical, nor is the cluttering of the background with a detailed treatment of pictures and furniture.
Honoré Oaumier was a master of telling understatement, he suppressed fussy detail in favour of unadorned truth.
This sketch is an example of mid-nineteenth century titillation, showing a group of connoisseurs gloating over an artist drawing a voluptuous model posed in a mildly lascivious fashion. The draughtsmanship is competent rather than inspired.