For insight into the work of a copy editor, check out this interview with copy editor Susan Bradanini Betz. The interviewer is writer Edan Lepucki, who has been copy edited by Betz.
I particularly appreciated what Betz had to say about being aware of a writer’s style and what the writer is trying to accomplish. I just finished reading Ali Smith’s There but for the, and I imagined Smith’s copy editor starting to edit this work, making a few changes, and then throwing in the towel, sitting back, and enjoying the ride. Did Smith mean to do that? What about this? (What about there, but, for, and especially the?)Yup, she meant it all, and I admire the copy editor who let it — the dialogue, the wordplay, the lack of punctuation — all stand.