Marianne Theodorsen of Style Devil, before Dries van Noten, Paris, October 2015.
Wide leg jumpsuit with preppy striped button down shirt. Love those cute suede sneakers — comfy, practical and stylish. 
Recreate Marianne's look (kind of):
Jumpsuit: Nomia Wide-leg sleeveless jumpsuit, MM6 Maison Margiela knitted wide-leg jumpsuit, Joesph Tish crepe jumpsuit, Opening Ceremony Talene U Neck Jumpsuit, ASOS Jumpsuit with pinafore detail, BCBG jumpsuit, or Whistles Bey Crepe Jumpsuit with pockets
Striped shirt: Toteme Capri striped shirt, Rag & Bone/JEAN Striped Boyfriend shirt, J.Crew Boy Shirt in bold stripe, Equipment Daddy shirt or Current.Elliott The Prep School shirt
Suede sneakers: Eytys Mother suede sneakers (in black) or grey, or Common Projects Suede low-top sneakers