Metaphor
Like dreams and shamanic journeys, our whole system, individuals, internal landscape and personal imagery can be full of rich metaphors.
My personification of an Encryption Algorithm took on a persona, and has a startling resemblance to a female version of my father-- the metaphor for strength, deep and explosive anger, being in charge, etc. that I needed to foil my abuser. Some of the Internal Objects in my system are metaphors for keeping track of information such as a journal and a file cabinet. Guardians will often take on fierce and strong personas, often dangerous mythical creatures of great strength such as demons, giants and dragons.
Also check out Analogies for Plural, Multiple & DID Systems New.