The icon to use for the application. This can either be an absolute path to an image file or an icon-name. If an icon-name is provided an image lookup by name is done in the user's current icon theme. The xdg-icon-resource command can be used to install image files into icon themes. The advantage of using an icon-name instead of an absolute path is that with an icon-name the application icon can be provided in several different sizes as well as in several differently themed styles.