I think Kate's dress is fine for a casual dinner at home. Well, "casual" in her world. I think the high waist is strange but she seems to like them. I think the length is a flattering one on her. I like the print of the dress. As with everything she wears, it would look far better if she stood up straight.
I wonder if she and William and Harry intentionally dressed in blue? I do wish those two blokes would wear something other than that particular blue. They've got it in casual trousers and jackets as well as suits. Obama's black outfit looks far snappier than that blue, which I don't like at all unless it's denim, but then I always think men look better in black or charcoal than any other colour. At least Harry has added a bit of zazz to his outfit by wearing blue suede shoes.