A painting is done when the artist says it is done. I once saw a painting for sale where someone (other than the artist) added a butterfly to an otherwise wonderful picture of a meadow. The butterfly totally ruined the picture. The artist had called it done but a non-artist decided that their untrained eye said it needed more so they kindle added a butterfly thus yielding the painting worthless. If you made a dress and everyone said it needed or lace or ribbons or embroidery or ruffles or a shorter or longer hem or nec and you made some or a bunch of these change, it would no longer be your dress but a dress designed by a committee who were not part of the design from inception to completion.