The uncarved block represents the ultimate art form, since in potential, the uncarved block can be everything. However, Taoists are human loving to give in to emotions, whimsy and freedom to just let go. To let the art take the artist to the wildest heights.
This is an example of a Taoist letting go. Taking the uncarved block of wild boulders, and seeing in it themselves. Our very nature within the rock.
We are many things in life, including at times: rock. Our potential is what we might be and reality becomes the shape we carve out for ourself. Ideally, we leave our shape un-touched, un-formed so we can experience life fully.
In a strange manner much of Taoist practice reverses the shaping that we do upon ourselves. We can start off as one shape, to let go of form, to then become whole and uncarved again.