"the visiting card of a brothel in Paris"

The French have taken a decidedly relaxed attitude towards prostitution over the centuries.  Given that regulation at least offers some protection to the women involved, we can consider Napoleon as the authority who best attempted to establish some semblance of structure around the 'world's oldest profession'.  By 1804, all prostitutes had to be registered, and received health checks twice a week - though this was as much for the clients' sake as for theirs.  Brothels came under control of the State, and had to be run by women, but conditions varied and many prostitutes endured long working hours.  Whilst some brothels were extremely down at heel, others were the height of luxury; one example was 'Le Chabanais', which opened near the Louvre in 1878.  Lavishly decorated due to enormous contributions from private investors, it offered rooms in different detailed and distinct styles.  Its 'Japanese' room even won a design award at the 1900 World's Fair in Paris.  Patrons of the brothel included Toulouse-Lautrec and Guy de Maupassant; later, King Edward VII, Cary Grant and Humphrey Bogart were all visitors too.  Establishments such as these and 'Le Sphinx' were able to offer clients whichever 'scenarios' they desired - such as the one described here in the story - until brothels were outlawed in 1946.