An incomplete metaphor of the things Donantonio could support is the "astral metaphor".
If we believe to some astrologists, the physical body has an astral body (the soul). In some circumstances the soul can travel without its physical body. But soul and body are linked with a silver bow. The astral body (the soul) can travel to any place of the world and ever is linked to his body, which is still sleeping somewhere on the Earth. But if the silver bow get broken, the soul is not linked to its body anymore. It's the death for its body.
For Donantonio thinking, documents are the body, descriptions are the astral bodies of its documents and are linked to it by a URL.
If the link get broken the description lost all is usefulness and the documents die forgotten in somebody hard disk.
The principal idea is that while resources are sleeping in some place, their souls are traveling along the world, being processed and shared between Donantonio appliances. Donantonio add the ubiquity faculty letting several duplicated souls for a only resource