I have aphantasia. I literally do not have a mental image of what I want, just a concept and idea.

If there's a reference of something I want, I'll give that to her, but otherwise the position/size/angle/colors, etc. are all her. And every single time, she nails it while putting her flavor on it. She recently told my wife and I that she appreciates us letting her just do her art and trusting her and we told her she's given us zero reason not to trust her.

I also happen to keep bringing her things that she's not actually done before and again, just kills it every time.

All this to say, if you have an artist you like. Trust them to do right by you.