Margaret Zhang of Shine by Three blog, before A Show, NYC, September 2015. Another version (and another way to style) the backless button down shirt!  
Recreate Margaret's look (kind of):
Dion Lee Open-back cotton poplin shirt
Flare skirt: The Fifth Label Just for Now skirt, Tibi Esquire Fluted skirt, or Maiyet Flare skirt.
Open toe pumps: Tibi Leona mules, Vince Faye open toe booties, Balenciaga open toe ankle booties, or Maison Margiela open toe booties