I can answer your question since I've defined the contexts from which I'm coming from. Ladies are not seen as gamblers; perhaps internet casinos that do KYC might justify the response better, but you will rarely find women in general who like gambling.
I think the OP is looking at it from the point of view of other gamblers who incidentally are men, in this case, not from the employees who are there.
I think the parable is quite simple for OP because just imagine when we are in a make up class which is attended by most of the women and we as men come alone there, of course we will look striking and will be the center of attention as well as when girls are in gambling then of course there will be lots of pairs of male eyes who want to see her.