Subsetted font slightly different in FontSquirrel generator

[Zsolt Ero]

I'm using pyftsubset to subset a font (Lato) to European characters and then submit it to FontSquirrel generator.

The command I use is the following:

pyftsubset Lato-Regular.ttf --text-file=small.txt --text=' '

My problem is that the subsetted font differs slightly from the non-subsetted one, after running both through FontSquirrel's generator. Especially with vertical spacing / margins.

Is there a default option which might be causing this?