These screenshots speak for themselves:
http://osu.ppy.sh/ss/4133
http://osu.ppy.sh/ss/4134
In nutshell, there is a gap below difficulties of selected song, and the more difficulties, the bigger the gap is.
http://osu.ppy.sh/ss/4133
http://osu.ppy.sh/ss/4134
In nutshell, there is a gap below difficulties of selected song, and the more difficulties, the bigger the gap is.