Hi Harm, honestly because I generally understand "padding" as the amount of whitespace that should be reserved between objects. I never even noticed that property since in my mind I was looking for something that could in no way have something to do with it. Anyways, it's not the first time I find some of the Lilypond naming misleading, it's probably not going to be the last, but after you explained I can *kind of* see why it was named like that.
As always, thank you for your input!