This functionality allows for an Expert site to display multiple ways to sign in to the site on one page. Sign in links throughout the site as well as the sign in flow to view private, permissioned content will redirect to this custom page, allowing for a personalized user experience.
Without custom branding, the default design is a simple responsive layout with links to each configured identity provider service, including the local identity provider service, which displays the built-in authentication sign in form.
With custom branding, the links can contain custom images or icons, titles, or messaging.