At its most basic, editing is making changes to a written text. Simple enough, right? And yet, not, because folks have different understandings of when it is okay to make those changes.
Case in point: I once knew a writer-turned-editor who felt “editing” meant she always needed to make a change to the original text, sort of as a way to prove that it had, in fact, been edited. This led to a lot of ridiculous edits, such as the substitution of a word with its synonym: ex. “Clifford the big red dog liked to play” would become “Clifford the enormous red dog enjoyed playing.”
The original meaning of the sentence wasn’t changed or improved at all by those kinds of edits; many of the writers she worked with felt like she was just wasting everyone’s time and was only interested in her own self-aggrandizement.
On the small scale, this kind of substitution editing can be harmless to mildly annoying. On the large scale, it meant the editor was taking a lot of her time completely rewriting copy, without a good reason for it. (When asked, she said, “I thought it sounded better.” That… isn’t a reason to make edits.) Her editing ethos was: “The editor knows best.”
Basically, she was the Loki of editors:
Is there a better way?
I think so. My editing philosophy is: “First, do no harm. Second, make it better without impeding the author’s voice and meaning.”
In other words, it is never my job to make a change just for the sake of making a change. If I were hired to copy edit a piece and I couldn’t find a single mistake, I’d congratulate the author for doing an excellent job (I’d also want to shake their hand, because that’s a feat!).
An editor is really second fiddle to the author. Particularly in the changing publishing marketplace, an editor acts as adviser and clean-up crew–but the author is the boss. When I make edits as a freelancer, I always provide complete transparency, using Word’s Track Changes feature to literally show each and every change. If a change is subjective, I leave a comment explaining my actions. Then it is up to the author to decide which changes to keep and which to disregard.
Editors are powerful, it’s true, but at the end of the day, they–like our pal Loki–are small gods.

Author Hulk here is expressing his feelings toward his overly intrusive editor, Loki.