This is the output from git diff --stat
It indicates the changes like you've said it already.
git diff --stat is console width agnostic. It's either the exact amount of changes or it's just a percentage of changes.
Given git diff --stat -w100 and you are diffing 2 files width 1000 changes, then the output will be blurred, to fit into 100 chars output. Not sure how to explain it better.