She's the (new?) face of St. Tropez sunless tanning -- this is not a sponsored mention, although that is an affiliate link, but St. Tropez is pretty good as far as that goes! (I generally get a professional spray tan but sometimes you need an at-home touch-up!) -- so it explains that she's out and about in white, the better to show off her faux tan.
Honestly, I think she looks absolutely great -- but they couldn't send her to actual Saint-Tropez for the promo? RUDE!