Clarify effects restricting Public visibility on user info

doc/user/admin_area/settings/visibility_and_access_controls.md

@@ -188,6 +188,9 @@ To restrict visibility levels for projects, snippets, and selected pages:
 1. On the left sidebar, select **Settings > General**.
 1. Expand the **Visibility and access controls** section.
 1. In the **Restricted visibility levels** section, select the desired visibility levels to restrict.
+   If you restrict the **Public** level:
+   - User profiles are only visible to logged in users via the Web interface.
+   - User attributes are only visible to authenticated users via the GraphQL API. 
 1. Select **Save changes**.
 
 For more details on project visibility, see