So, what would an un-narrow ruling have looked like?
As the articles state, it would have dealt with broader issues, such as the 1st Amendment freedom of speech (or silence) and freedom of worship (or non-worship) issues that claiming that someone is entitled to a (transient, in this case) work of art that carries a specific message from a specific artist who does not want to create a work of art with that message because he believes it to contradict the tenants of his religion. As it is, this is about the fairly narrow 5th Amendment matter of were his views on the message he was being asked to convey treated in the same manner as the views of any other artist being asked to convey the message of a prospective client which the artist does not believe in personally (which they were not, which is the basis of the ruling as I understand it).
Appellate courts generally seem to like making narrow rulings on the basis of procedural protections to end cases like this, probably because it means they don't have to think about the bigger questions, like whether it is permissible for the state to require speech that the speaker is, in fact, personally opposed to. (Living in Canada, I have to deal with the fact that I am under a legal system that explicitly refuses to accept that a thing is done freely only if one is also free to NOT do it, such as I only associate freely with a person if I am also free to NOT associate with that person. Here, we're going through a spasm of insanity from our idiot Prime Minister who thinks he can put you in jail for not using random nonsense instead of correct words because he just doesn't like the correct words.)