I understand his analogy, but really, nothing is made from the outside in.
And the "creation" begins with the thought.
What he needs to say is something much simpler. There are two ways of becoming. Compare carving a statue of a lion out of a block of marble, vs. a newly-begotten lion gestating in a lioness' womb.
The block of marble could end up being anything -- a statue of Diana of the Ephesians or a tombstone or a pile of ashtrays --- because it is an article of manufacture. It is not "lionish" from start, and does not develop spontaneously through the various characteristic leonine stages.
But a lion whelp is lion from the start, derives its nature from the fact that it has a lion sire and a lion dam, and develops itself from its own plan, from within, given an appropriate environment with time and nutrition.
It's not just a matter of "thought," because thought goes into, for instance, the blueprint for a house. But you can't plant a blueprint in the ground, and get a house. It does not have a nature that unfolds from within.