Lookbooks include a Sign In and Sign Up button so that clients can view their previous looks and manage their accounts & billing details.
Clients whom you've shared looks with can click Sign Up in order to set a password and access their account for the first time. If they've already set a password, they can use the Sign In option.
Clients can also sign in through your profile page. Clients cannot log in on Arthur's homepage (www.arthur.shop).