I'm guilty of clothes shopping and being drawn to similar shapes, similar colours to what i already own. I begin with great intentions to branch out a bit, but seem to go into a trance, hone in on the familiar and realise i've bought yet another x, y, z. At clear out times i'm horrified by all the sameness in my wardrobe and year on year i promise myself to stop doing it but i can't seem to!
Maybe something a bit like that is going on with Kate?
Personally I think she looks great pretty much all of the time and honestly i think her slim figure photographs well and is all part of the 'look'. Smart, structured and very disciplined. I'd strive for the exactly same in her position.