For a first instance the Freedombox admin user who installs the package will become a zoph administrator. Zoph authentication is done via Freedombox, but zoph rights are managed via its own system. Sharing of individual photos is done by sending a link which is unique to that photo, so does not require the recipient to have an account. Sharing via the link only gives access to the photo, and not the information such as the people in it.
Putting it behind Freedombox authentication means that zoph guest access will not be possible. Note that zoph is aimed at being a Photo Organiser, rather than a gallery, and I see that main use as being people with thousands of photos, who want to be able to manage them. I am hoping people with big photo collections who currently share them though Dropbox, Google Drive, Facebook, Flickr etc will find a Freedombox an easier way to manage their photos, and then find that they can do other things on it too.