From the always-wonderful Underpaintings 'blog,
Titled, "l'Atelier" by Horace Vernet, 1822
All the contemporary paintings I've seen of the old classical ateliers make them look like a kind of gentlemen's clubhouse or a men's version of the ladies' salon. A lot more than just drawing and painting seemed to go on in them. Doubtless there was lots of interesting talk about art, politics, religion etc. Several of these people are smoking!
I wonder how much the infiltration of women into this masculine domain, that started in the 20th century, contributed to the collapse of the classical atelier tradition in art instruction.
For my part, it looks irresistably fun, interesting and attractive. If I had lived at that time, I'm sure I would have found the company at such a place above much more engaging than a dull, stuffy salon any day. (How many salons included spontaneous fencing?!) So I can understand why chicks wanted in. Women are boring. Men are fun.