Difference in downloaded GIMP dmg file size

[Sadioga]

File size said here is 56
https://download.gimp.org/pub/gimp/v2.8/osx/
gimp-2.8.20-x86_64.dmg 05-Feb-2017 19:56 56M

But the dmg file I got is 58.8 MB.
I have heard that could be bad sign? Or is this normal?

Also, is is safer to use site's own download over their mirrors?

Like said here:
https://www.gimp.org/downloads/
The download links above will attempt to download GIMP from one of our trusted mirror servers. If the mirrors do not work or you would rather download directly from our server, you can get the direct download here.

 

[lostless]

Its normal. Mac OS counts real ones and zeros while the rest of the world uses the actual 8 bits/byte. Meaning instead of 1024 bytes = 1kB Mac OS shows 1000 bytes is 1kB. In the end file sizes look larger on Mac os