Unity greeter removes the Ubuntu logo by default on singular session (Ubuntu 12.10)

Along with numerous overall user interface changes landed in Quantal, Unity greeter has received minor yet numerous refinements, transforming the greeter into a more polished, visually precise and worked-on-detail login experience.

The latest updates bring a new version of Unity greeter in Quantal Quetzal, further adding subtle user interface changes.

At login, in order to select a different session, the user clicks the login box's Ubuntu logo, action that exposes the available sessions on the box, clicking on a session (such as GNOME), opens the clicked session.

The newly landed Unity greeter removes the Ubuntu logo button from the login box (the default behavior) if there is only a session installed (installing Ubuntu, automatically installs only a session, Ubuntu), probably due to the fact that having only a session installed on Ubuntu, transforms the Ubuntu logo into a completely unusable (without purpose) icon.

Yet, adding extra sessions (like for instance, installing GNOME Shell), adds the BFB icon to the login box, allowing the user to select different session (following the regular login box's usage behavior).