@Matthew-Oberdier just like in any other job, every client is different. In one 3PP podcast, the guys talked about how the bigger the publishing house, the more creative freedom they got. While I haven't worked with any big publishers yet (or even mid-level), it's been my experience that the very small publishers I've worked with have given way more creative license than some self-publishing clients I've had.
That's not to say that all self-publishers are control freaks. They're not. But one of the reasons many choose to self-publish is that they want more control over the process. That translates over to working with an illustrator. Some self-publishers have been specific in their illustration notes -- they basically wanted an illustrator to be their hands to paint the picture they envisioned in their head. It can be a frustrating situation for both parties.
But like I said, that's not everyone. I've had awesome experiences working with self-publishers, too. One of my current projects now is working with a self-publishing author for the second time. They've been great -- we keep communication clear and honest, talk about the scenes and characters, and then they basically say "go do your thing." So yeah, some self-publishers are very happy to give illustrators creative license.
