You do realise the term "party girl" is commonly used escort jargon for drug user, don't you?

Maybe they know the full meaning of partygirl and want to attract those type of escorts.  (I'm not slagging off any escort off who takes drugs that's completely her/his business and choice)

I associate partygirl with escorts snorting coke with clients. Other agencies market escorts who partake in drugs, (especially coke) as escorts who enjoy white wine. And some agencies will even market escorts as partygirls can bring the party to you. (Code for getting drugs for client).

Partygirl is a widely recognised term by punters for escorts taking drugs.

Also they are accepting payment via paypal! They obviously don't know how to run an escort agency or other adult business. I mean payments via Paypal. Don't make me laugh!