Why Barbie Trades Chanel For Birkenstock, According to the Movie's Costume Designer

PS: What was the inspiration for the Barbies at the block party?
JD: At the block party, I referenced and copied a lot of different Mattel historic costumes from different eras and epochs, but what I did is I asked the Mattel HQ to send me references of all the Barbie costumes over time that were white and gold. So they sent those to me, and then I chose from that selection different Barbie styles to replicate for the movie.