Chrissy Teigen just made a sack the classiest thing we've seen all week. Teigen pulls it off because she's Chrissy Teigen; the rest of Us could use a little more shape and this tailored-looking version does it perfectly. It's equally effortless and stylish, but is much more flattering. A few days ago, Teigen posed on Instagram wearing a $1,900 Balenciaga sack dress, a slouchy, structured-yet-shapeless number that somehow just works.