Meghan wore a lace A-line dress by cult UK brand Self-Portrait, a favourite of Kate Middleton.
Despite the fact that all we have are these grainy, aesthetically displeasing photos, keen-eyed fans were able to quickly identify her frock as the Self-Portrait Nightshade Midi Dress.
Unfortunately - but true to form - the dress sold out within seconds thanks to what we're now dubbing "The Meghan Effect."
The Duke and Duchess of Cambridge were also seen arriving to the Queen's household minutes after Harry and Meghan. Prince George and Princess Charlotte sat in the back of the car, with their nanny Maria Borrallo.