The former Made in Chelsea star kicked things off with a chiffon flowing maxi dress, by designer Luisa Beccaria, at the John Frieda cocktail party also attended by Amy Willerton, Lucy Watson and Stephanie Pratt.
But instead of swigging on champers, Millie took to the top of the tower for a camera-worthy stunt, throwing her 'hair' down the length of the building Rapunzel-style, to celebrate the brand's new campaign.
Millie later switched into a shorter frock from Free People, adding an edge with a black leather jacket.
She paired her boho ensemble with her trademark glowy skin and super-glossy tresses.
Does the girl ever put a fashion foot wrong?!
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