I’ve tested on r1717, and can confirm that you associate more than one image to a dmi criteria, and will get a message to that effect on the client, and asked to choose which one.
see attached screen shot, for info I have the dmi field set to serial number.
[ATTACH=full]828[/ATTACH]
[url=“/_imported_xf_attachments/0/828_capone_multi.png?:”]capone_multi.png[/url]