Hominis keeps each site’s cookies separate from the sites that embed it, so a service embedded on many pages can’t follow you from one to the next. Some embedded features, such as a comment box or a sign-in button, only work if they can reach their own cookies. They can then ask for access.
If you allow it, the embedded service can use its cookies on that site only. To review or remove the permission later, click the site’s icon on the tile header to open the trust panel, where it is listed under Permissions.