You can get very creative in your instructions to a human, but that creativity still won't get you any copyright.
And afaik, in a work for hire scenario, the artist just agrees to transfer their copyright automatically. If there's no copyright in the first place, there's nothing to transfer
And afaik, in a work for hire scenario, the artist just agrees to transfer their copyright automatically. If there's no copyright in the first place, there's nothing to transfer