What is in the export report?
Every time you export an interior, a — report.txt file downloads with it. It's plain text, it's meant to be read, and every number in it was measured on that export — nothing in it is estimated or generic.
Keep it. If you ever need to ask what happened to a book, sending this file answers most of the question before it's asked.
What we changed from your file
The honest accounting of what the formatter did to your manuscript: paragraphs and words read, chapters found, straight quotes converted to curly ones, lines broken with a hyphen, front-matter pages built, blank pages inserted to keep chapters on the right, and how many pictures were placed.
The picture line reads like "354 (2 distinct files)" when a book reuses the same ornament over and over — the first number is how many times a picture appears on the page, the second is how many different image files that took.
Your settings
Every setting the export ran at, with a Changed from default block listing the ones you moved. This is the section that tells you what "the version I liked" actually was, six weeks later.
The book
The finished physical facts: trim size, page count, body typeface, size and leading, the measure in inches and in characters, lines per page, margins, and the gutter.
The measure in characters is worth a glance — the trade norm is roughly 60 to 72 characters a line. Much under and the text feels choppy; much over and the eye loses its place returning to the left margin.
How it was set
The quality measurements, and the part most worth reading:
- Word spacing — the median gap as a multiple of the font's natural space, and what proportion of gaps are noticeably wide.
- Even color — how often two stacked lines have visibly different spacing. Higher is better.
- Page fill — the proportion of pages ending level, and how many spreads are uneven. See What is Page fill, and what is a river of white?
- Line breaking — the proportion of lines ending in a hyphen, and the longest hyphen ladder left in the book.
- Refinements applied — ligatures, letter-pair spacing, and how far glyph-width fitting had to go.
Things to look at
Not errors — things a careful reader would want to know about their own book. Blank pages inserted and why, pages that run short of the bottom, rivers of white and how far they run, a word broken across a page turn.
The last line is the useful one:
N places where a few words would make a chapter's pages run level.
That's an invitation to fix it as a writer rather than as a typesetter. Open the book in the formatter and it will show you exactly where — cutting or adding a few words in those chapters closes the gaps without spending anything on word spacing.