Innumerable pearls line the blue satin dress of the Honourable Frances Duncombe, who wears a bright red jewel on her chest, possibly a ruby or garnet. Frances was raised by her stepmother in the house of the Earl of Radnor and was betrothed to the earl's eldest son. However, her engagement was broken off when the family discovered her affair with a John Bowater, whom she married in 1778. Exactly when and why this monumental portrait was commissioned from Gainsborough is unknown. After spending some years living in Germany (rumoured to have had an affair with Archduke Maximilian Franz, brother of the French queen, Marie Antoinette), Frances returned to England and lived with this portrait in her family home, Old Dalby Hall, in Leicestershire, until her death, in 1827.

Mizrahi's creative contribution adds greatly to this book about this iconic painting of a fashionable lady. He mentions the moment of first catching a glimpse of the work when seeing it unframed. "I gasp. Frances Duncombe looks every bit as gorgeous unframed, if not even more so for the vulnerability."

Isaac Mizrahi is an actor, host, writer, designer and producer as well as chief designer for the Isaac Mizrahi brands, a division of Xcel Brands, Inc. 

Aimee Ng is Peter Jay Sharp Chief Curator, The Frick Collection, New York.