I've reported a bug on Zentyal (ticket 2678 though it hasn't put it fully onto its database as it's not retrievable even as one of My Tickets). Hopefully, this might make zentyal-package work as per the documentation on
http://trac.zentyal.org/wiki/Document/Documentation/ZentyalDesktop/Ubuntui.e. the user (as defined to Zentyal) and their home directory is created by a script located at /usr/share/zentyal-desktop/zentyal-setup-user - implied by screen shot showing a keyed-in Username with Other.. showing on the Ubuntu Login window.