Roman goddesses

Posing for a painting, I assume

It's something that was done in upper crust society at the end of the Victorian era. It made them feel special that they could appreciate such high-minded culture.

If I recall correctly, it was called making a "tableau," a classic scene from ancient literature or history. It was all just modeling for its own sake, not for a painter or photographer. Sometimes, photographs were taken, which is how we have the visual evidence in social histories and such. It was all just for the edification of the posers apparently. An alternative to tea and bridge and such. Women had fewer recreational outlets in the male-controlled society of the day.