King Charles and Queen Camilla were joined by senior members of the royal family at the annual Garter Day procession in Windsor on Monday.
As they led the procession to St George's Chapel, the monarch and his wife were accompanied by the Prince and Princess of Wales, the Duke and Duchess of Edinburgh and the Princess Royal.
Amid the pomp and ceremony, there was one particularly sweet exchange between Duchess Sophie and Princess Kate that almost went unnoticed.
Ahead of the procession, the royal pair were seen chatting animatedly alongside another guest inside the Galilee Porch at St George's Chapel.
According to professional lip reader Nicola Hickling, Princess Kate appeared to offer a few reassuring words to the group, telling the pair: "Oh you look good, don't worry," which prompted Sophie to chime in with a laugh: "What do I look like?"
For the summer outing, Princess Kate looked beautifully regal in a white peplum-style outfit crafted by Self-Portrait. She teamed the ensemble with a saucer-style hat by Sean Barrett, and elevated her look with timeless pearl jewellery.
As for hair and makeup, the mother-of-three wore her chestnut tresses down loose in rippling waves. She accentuated her eyes with smokey eyeshadow and added a slick of rosy pink lipstick for a hint of colour.
Duchess Sophie, meanwhile, looked her usual stylish self in a pastel pink dress by Suzannah London, complete with a cinched-in waistline and a flattering A-line skirt. She accessorised with a chic wide-brimmed hat, some strappy heels, a gem-encrusted clutch, and pearl jewels to match Kate's.
Kate and Sophie's close bond
Over the years, Princess Kate and Duchess Sophie have forged a close friendship. The pair have shared royal responsibilities, and are regularly seen supporting one another on outings such as Trooping the Colour and the annual Service of Remembrance.
HELLO!'s Online Royal Correspondent, Danielle Stacey, previously told us: "It's no surprise that the Princess of Wales and Duchess Sophie have such a close relationship. No doubt Sophie has been a huge support to Kate over the years, especially when Kate first joined the royal family in 2011.
"The royal ladies have similar interests and passions, including their love of sport and fashion. They also share common causes within their royal work, with both Kate and Sophie championing the work of children and young people's charities."
It seems likely that the pair have also traded parenting tips over the years. While Sophie and Edward are doting parents to Lady Louise and James, Earl of Wessex, Kate and William are busy with their three children, Prince George, Princess Charlotte and Prince Louis, whom they welcomed in 2018.