This issue is indeed a conundrum. I recently thought I had finished a piece called "The Eye behind the I Am". I kept looking at it knowing in my heart of hearts it wasn't yet done, but I couldn't face that fact, as I could see nowhere to move the drawing forward.
My son recently on Spring Break in a visit to my studio confirmed that it wasn't finished. How is this knowing arrived at? I look at the piece and get pleasure from thinking of the idea the piece was trying to explain. However it looks hollow and shallow and doesn't allow my mind to wander off to other places, I am stuck with this one idea. This is an illustration. Now the eye shape that is behind the "I am " is I think a brilliant concept, but visually it needs more fleshing out.
How to be the thing ,rather than to illustrate the idea of the thing. This is such tricky territory, yet we all know it when we see it. I will show two of the many drawings I made to help with the work, and then its back to the drawing board, or I may put the piece away for a while.