Robert Louis Stevenson describes how a work of art changes in the translation from inspiration to execution.
"A work of art is first cloudily conceived in the mind; during the period of gestation it stands more clearly forward from these swaddling mists, puts on expressive lineaments, and becomes at length that most faultless, but also, alas! that incommunicable product of the human mind, a perfected design.
"On the approach to execution all is changed. The artist must now step down, don his working clothes, and become the artisan. He now resolutely commits his airy conception, his delicate Ariel, to the touch of matter; he must decide, almost in a breath, the scale, the style, the spirit, and the particularity of execution of his whole design."
Painting by Rupert Bunny, (Australian, 1864-1947) "Pastorale." Here's a big file on Wikimedia Commons (Thanks, Mike Dubisch)
Robert Louis Stevenson, Essays in the Art of Writing