Install unity-greeter-badges by entering the following commands in the terminal:
sudo apt update sudo apt install unity-greeter-badges
Description:
Additional badges for Unity Greeter
This package adds additional badges, i.e., the icons that appear next to each desktop environment, in Unity Greeter, Ubuntu's default display manager. It adds support for a wide variety of desktop environments not supported by the default Unity Greeter installation, e.g., MATE, Cinnamon, Window Maker, and more.
Homepage: http://gnome-look.org/content/show.php/?content=158764
Version: 0.4-0ubuntu3
Section: universe/misc