I have come to realise that a keypiece is a catalyst. It is a physical manifestation of a mental state but the importance is the change in mental state, not the artefact.
A keypiece does not have significance outside its context within my creative process and it's status can only be recognised by me or someone deeply embedded in my creative process.
For me, a keypiece looks forward as well as back; it is not solely a conclusion or a starting point, though it can be both of these things as well. It can be recognised in the moment or in hindsight but not anticipated.