Are you talking about text or image?
Text is simple. Simply code in the "Do Section" or "After Last Object Printed" the media objects system function for the particular queue you're looking to retrieve from. Pass in the action "<Get Text>" and retrieve in Text the variable you wish to report. You will also have parameters depending on which Global Text field you select.
That's the simple way. The more complicated way (like we had to do back in the stone ages before Xe in B7.3.1 and B7.3.2) is to write a business function to retrieve it. I can get you the code for that if you decide you need to go that way.
To get an image... I'll have to think on that one. I don't know that UBE has the capability to do that without calling the UBE engine directly using undocumented APIs. I have always been able to talk the client out of doing that. You can create a new font and put signatures or logos in it, but as far as retrieving an image from media objects, there's not a simple way that I know of. I expect that using a business function, an image could be rendered, but I've never done it, YET.