As one branch from the Maison Estelle brand, the members club portion of the site creates its community. It filters to make the right people enquire for membership. They have to feel "ah, this is for me". And repel tire kickers that wouldn't feel at home and embrace the benefits that the members club was made for.
Often this is achieved using intentional photography of people that signal who an offer is for. For Maison Estelle, they've prioritised privacy of their members, and share something important: the people who belong there don't share common looks, style, or attitude. They share common interest.