The first girly doesn't have the awkward gawkiness of the second one. She looks comfortable and therefore the dress doesn't look so awkward on her - but bloody hell, yo, whoever came up with such a stupid design for a dress! It looks ridiculous!
Don't like the dress at all. I think Kim's hips are curvier, so the bottom-half suits her, but Michelle's shoulders aren't as broad, so the top half suits her. xD Could be Kim's pose that's helping bring her curviness out, though.