black formal cocktail dresses Rihoas Elegant Tie Strap Maxi Dress Chiffon Slit Dress for Wedding Guest, Party, Evening Party, Black / XS allowing easy movement while keeping the dresss shape and grace Dylan & Davids Elegant Lace

Either a waistcoat or a cummerbund is required to cover the trouser waistband, but you should wear one or the other, not both

The dramatic bell sleeves in delicate floral lace add a bohemian touch of femininity and movement, making every gesture graceful and captivating

Here's the original photo of the dress alongside some other photos with helpful color context: You can watch the full ASAP Science video below:

Take a look back at our Spring 1992 collection featuring supermodels like @NaomiCampbell, Linda Evangelista, and @tyrabanks

Princess Diana was well aware of these sartorial stipulations, and, perhaps, was sending a rebellious message to the monarchy by wearing a look that pushed the envelope