The display of "unmatched bytes" is confusing in a Diff Window.
If there's a one byte difference in the same place in both files I would expect "unmatched bytes" to show 1 instead of 2 bytes.
However, it does show 2 bytes and I assume it means that this is the count for BOTH files. I think it might be a better choice to show this value for both files to make it more clear what this value means.