Wrong.
Copyright is absoulutely NOT flexible when it comes to artwork.
This is exactly what copyright is intended to protect: the ability of a person to commercialize their own work and prevent others from commercially benefiting from their works without their permission.
Bottom Line: The only person that has the right to reproduce a work is the copyright holder. Period.
Quote:
Title 17, Chapter 5: Copyright Infringement and Remedies
§ 501. Infringement of copyright3
(a) Anyone who violates any of the exclusive rights of the copyright owner as provided by sections 106 through 122 or of the author as provided in section 106A(a), or who imports copies or phonorecords into the United States in violation of section 602, is an infringer of the copyright or right of the author, as the case may be.
[...]
§ 106. Exclusive rights in copyrighted works36
Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following:
(1) to reproduce the copyrighted work in copies or phonorecords;
[...]
If you don't believe this, handpaint a picture of Mario, put it on a T-shirt, and sell them in front of Nintendo's office... see what happens. 
