SAML V2.0 Metadata Extensions for Login and Discovery

A quick comment regarding the SAML V2.0 Metadata Extensions for Login
and Discovery User Interface Version 1.0:

http://wiki.oasis-open.org/security/SAML2MetadataUI

The <mdui:Logo> element is fine as far it goes, but what about icons,
background images, etc.? I doubt the intent is to accept all kinds of
images in this element, so my question is: What if the entity wants to
include pointers to other kinds of images?

Thanks,
Tom