Boat on the Bay
Being finished is really just being in a state of grace. You have arrived at a place of equilibrium, everything that needs to be there is there and there is nothing that does not need to be there. In principle, you could be finished at the very beginning or it could take years to find that resolution you are looking for.
Being finished may in fact mean leaving some things unsaid. You are left with a question mark that leaves open the possibility of still more to come. Finished is more like complete rather than polished. A drawing is complete when it takes you somewhere, a painting is complete when it makes you feel something. These are states of mind that are open to interpretation. It is precisely that openness that invites, and it is the open invitation that makes your work finished.