I view developmental edits as a puzzle to solve.
Except the puzzle has already been put together.
And there's no lid.
The author has attempted their level best to write the book that's long desired to break free from their heart, mind, and soul.
And so they write word after word, page after page, chapter after chapter, until they have a book-length manuscript. But rarely is this first (or second or fifth) draft a book ready for public consumption.
That's when I'm often contacted to help.
To provide an unbiased opinion. To suggest ways to better cater to the reader. To help solve the puzzle of structure and flow.
In some instances, I'll pull the thing apart, using Scrivener to cut up chapters into discrete scenes.
Then, like an editorial Dr. Frankenstein, I'll put it back together. Some pieces may remain as before, but many are moved elsewhere. Some are heartlessly eradicated. A few tendons may be added to help hold it all together. Hopefully, the seams and stitches won't show.
In other words, I'll remove unnecessary pieces from the puzzle that were cluttering the message. I'll rearrange to form a more pleasing picture, one that tells a compelling story from beginning to end.
And hopefully the final form matches the lid that was always inside the author's mind, but they just weren't aware of it.