Artwork is not software. The four software freedoms don't apply.
Not all four freedom apply (as I wrote: artwork need not be modifiable) but
freedom 2 should still apply with the same rationale as for software:
(non-commercial) sharing is good and should never be forbidden. As rms would
say (
https://www.gnu.org/philosophy/google-engineering-talk.html#freedom-2-moral-dilemma
):
The most essential resource of any society is the spirit of good will, the
willingness to help your neighbor; not necessarily every time you're asked,
but fairly often. This is what makes the difference between a livable society
and a dog-eat-dog jungle. This spirit is not going to be 100% and it's not
going to be zero, but it's going to be somewhere in between -- and cultural
actions can influence it, can raise it or lower it. And it's essential to
work to raise it some, because that makes life easier for everyone. So it's
no accident that the world's major religions have been encouraging this
spirit of good will for thousands of years.
So what does it mean when powerful social institutions say that it's wrong to
share? They're poisoning this vital resource, something no society can
afford. Now what does it mean when they say that if you share with your
neighbor, you're a pirate? They're saying that helping your neighbor is the
moral equivalent of attacking a ship. Well, nothing could be more wrong than
that. Attacking ships is very, very bad; helping your neighbor is good.
And what does it mean when they establish harsh punishments for anyone caught
sharing? How much fear do you think it's going to take before everyone's too
scared to help his neighbor? And do you want that terror campaign to go on in
our society? I hope that the answer is no. We need to abolish the war on
copying that is being imposed on our society. We need to say, loud and clear,
copying and sharing with your neighbor is good, it's legitimate, and laws
that prohibit this are wrong.
So that's the reason for Freedom 2; it's essentially an ethical reason. You
can't live an ethical life if you don't have Freedom 2.