What's the word for the situation that a thing is X for A, but is Y for B? what property does it have in order to have this ability to shape-shift like that according to the perspective of the observer?
For example: I'm a father to my son, but I'm also a son for my mother. so what is the thing that differentiated between how my mom and how my son sees me?
Another one: a man's junk is another man's treasure: what's the property that this item has that it can be viewed by different perspective?
close-related words: role, position, identity, perspective.