Well, all serious offers she gets go through her management and I'm sure they will be discussed with her manager. But if she want advice about fashion I don't think she talks with Jonathan Dickins about that.
One of the most important people for her, is Michael Ashton, her make up and hair stylist. He has that Job now for three or four years. He is much responsible for her look in the public.
And you can be sure he provides her with the best products. If she makes a commercial for Dior or whatever than only with his advice and only with the best fashion line and not Diet Cola