It's from the third volume. Yabuki always makes that kid of special drawings for the tankoubon. It doesn't seem like the others were uploaded... I'll try doing it.
This might also be the best face he's ever done. The usual cat eye shape, the conflicted blend of grit, apprehension and desire, giving off that firm yet troubled, deep burning gaze, and she's not even one of my favorite characters. It's mesmerizing how when you start looking at the mouth alone, then add in the eyes, and finally the eyebrows you can watch her expression gradually form, subtly shifting with each step.
