The "sad girl in snow" picture was mentioned in MegaTokyo strip [75] and appears in strip [374].

Piro speaks:
For me, i've always been trying to capture certain feelings that you get in the fall and winter, usually the beginnings of it, when snow and crisp air and fall conditions have a refreshing, brisk quality to them (not the slushy duldrums that makes up most of the winters around here ^_^)
As for the 'sad girl in snow' shtick, the term itself was coined by the Mac Hall guys in a guest strip way back. It's always been an unconscious thing with me, enviroment, expresisons, moods, things you try to capture in a 2d medium (i dont even use color much).