When is it done?

I was working on a recent painting and was texting "almost" versions to a friend.  "Stop, it's perfect!" she pleaded.  I was at a loss in communicating why it wasn't perfect to me.  Yet.  So I kept going.  Two steps forward...one step back...for another week.  I kept reflecting on why or how I knew it wasn't done.  And then it became clear.  I need to keep painting, keep refining and reworking until I KNOW who this person is...and what she's all about.  Who is she?  What does she feel?  What is she yearning for?  Once I know, it's done.  It's a process of seeing their deeper soul.