"You have some very large shoes to fill. I hope you know that"
And Emily's obviously feigned irritation followed by a secret smile when Andrea offers her the clothes she got in Paris. It's the only time she looks happy in the whole movie.
Miranda's own When She Smiles moment in the car shortly afterwards. Particularly striking because Miranda actually smiles quite a lot throughout the film, but it's always been at photoshoots, public events etc., but here she gives a slow, gentle smile in the privacy of her own car, and it has a surprisingly transforming effect on the ice queen.
The revelation that Miranda gave Andy a glowing recommendation, outright telling her prospective employer that he'd be an idiot not to hire her.