This person can be a book publisher, a book cover designer for a publishing company, a book publicist, an editor, etc.. (iheartreading.net)
With traditional publishing contracts, there's less risk of getting a bad cover because they work with professional cover designers with genre expertise, etc.. (buildbookbuzz.com)
I'm a prospective book cover designer who's looking to get his foot in the door. (thebookdesigner.com)