This is about being able to configure the dock title appearance. It adds two new settings:
[GUI] showpalettetitles=false smallpalettefonts=true
Krita looks like this by default on OS X:
Yet having large palette fonts looks much more consistent and nicer, I believe:
For a minimal design, I think it also makes sense to completely hide the titles (while keeping the brush names big):
The latter version gives a cleaner look when using undocked palettes.
I wonder if this is something other users (apart from me) might like to set.