This feature is in reference to a custom onboarding experience we are working on that will use Audience Attributes to collect information on your audience that will then be able to be used in Segments and other areas of the app.
The Audience Directory would also use this information to help your audience find others in the audience.
To go along with this collection of data, you will also be able to provide videos during the login process of your Hub to help onboard your audience.