https://www.mediawiki.org/wiki/File:Whole_world_-_land_and_oceans.jpg
This image is displayed as 5.84 MB. In fact that is only true on Windows (5,83 MB to be exact).
It's wrong on all other OS like Linux and Mac where it's 6.1 MB after downloading.
The reason is that Linux based OS calculate B > KB > MB > GB by 1000*1000 bytes and Windows by 1024*1024 bytes.
MediaWiki should respect that and display the correct file size for the user by testing the
$_SERVER['HTTP_USER_AGENT']
Considerations:
- PHP caching could be a possible trouble maker tho.
- Javascript would be live but "flashing" since it's above the fold