After A Show, Paris, October 2016.
Layering: the bustier or corset top over a crisp white shirt. 
Recreate her look (kind of):
Corset bustier top — Marissa Webb Mae Pinstripe bustier top, Raey cropped herringbone corset top, Georgia Alice Void twill bustier top, Tibi Bustier Top, Laveer Bustier Suiting, Joseph Sydney cropped pinstriped top, Rosie Assoulin Cutout stretch-wool bustier top, or Elizabeth and James Nora ponte peplum top 
Plaid pants — Tibi Edie checked wool-blend culottes, Jacquemus Plaid woven straight-leg pants, or Petersyn Connery Pleated pants