When you create a deploy that includes multiple identical copies of the same file, Netlify will recognize the duplication and only upload once, saving deploy time and keeping our server storage efficient.
In the deploy summary for each deploy. We recently discovered that files with duplicates were being over-reported in this metric.
Thanks to @ingrid, that bug is now fixed, and file upload counts in deploy summaries now show the correct number of files, even when there are duplicates. 