The actress appears to have been inspired by the film’s costumes as she wore a black Gabriela Hearst Fall 2018 dress.
She typically gravitates towards colour. When she does opt for black, there are normally some details to enliven the inky base.
Here, there is the blue cording down the front and sides and the soft folds. I fear some might interpret the effect as messy, but had this been in a different fabric, the simple slip would have lacked presence.
Demonstrating a knack for subtle details, her eyes were awash with a bright eyeshadow to play up the trim.