Buro 24/7's Miroslava Duma, before A Show, NYC, February 2013.
Over-the-knee/thigh-high boots can be a bit tricky to wear both from a stylistic and fit perspective (those of us who struggle to find boots to wiggle over generous calves have practically no hope of finding a thigh high boot to fit!) but if you have Mira-size thighs, wearing them over super skinny jeans with a sweater is a lovely casual way to style them.
Recreate Mira's look (kind of):
Sweater: Tibi oversized turtleneck pullover, Topshop knitted ombre stitch jumper, Shae oversized waffle pullover, Penfield pocket sweater, Band of Outsiders Combat 2600 oversized mohair sweater, Stella McCartney oversized knitted sweater or Mulberry oversized checked knitted sweater 
Skinny jeans: Rag & Bone/JEAN high rise skinny jeans, J Brand 910 low rise skinny jeans, or DL1961 Emma legging jeans
Boots: Christian Louboutin Louise XI 120 boots, Sam Edelman Kayla Over the Knee boots, Sigerson Morrison Pearl suede flat boots, Robert Clergerie Fuji stretch-suede boots, or Stuart Weitzman 5050 stretch suede boots
Necklace: J.Crew Color Collage crystal necklace