The greeting string is the title of the login screen. If the string contains the word HOSTNAME it will be translated to the domainless name of the machine KDM is installed on.
KDM logo is the image which will be shown on the login window. If you do not
specify a logo the default $(KDEDIR)/share/apps/kdm/pics/kdelogo.xpm will be
displayed.
To change the logo you can:
As the style of the user interface is selected on a per user basis you can
also select which style should be used initially by KDM.
You can choose between Motif or Windows style.