LOGIN APPEARANCE
You can enable to configure the login dialog by adding following code to your Acl.php
$this->add(new Kwf_Acl_Resource_MenuUrl('kwf_welcome_form',
array('text'=>'Welcome', 'icon'=>'table.png'),
'/kwf/welcome/form'), 'settings');
Now it's possible to set a welcom- and login-picture as well as a text.