The report of someone dropping into Equinox was to complete their enrollment after signing up online and receiving the confirmation email. The email directed them to go to an Equinox location and present their ID and relevant Centurion card.

I have not yet received the confirmation email after enrolling via the link in my AmEx account, although it reflects that I am "enrolled." Not that I'm in any rush as I don't have an Equinox nearby. I had hoped the online enrollment would be a complete process so I could just drop by any Equinox when traveling but, based on the earlier report upthread, it seems one will have to visit a location to finish the sign up.