This adorable floral print dress is a great example of real vintage clothing being used for film and television. Costume designers often shop in vintage shops, but costume houses are also sometimes filled with genuine vintage pieces as well.
This dress was first seen on Ashley Judd as Vivi Abbott Walker in the 2002 film Divine Secrets of the Ya Ya Sisterhood. It was seen again on Sarah Drew as Kitty Romano in the 2008 second season episode of Mad Men entitled The Golden Violin.
This dress may or may not be the exact same one. A little bit of research uncovered that this dress is from the Vintage line called Cover Girl Miami, and that a surprising amount of these dresses still survive in good condition, which is rare for a piece of this age.