Fans noticed a distinct tribute to Princess Diana in the outfit the Duchess wore to announce the release of Hold Still.

At the start of this week, Kate Middleton announced the release of the photography book, Hold Still. Spearheaded by the Duchess herself, the book will contain images captured from the past year that highlight the trials, tribulations, and triumphs brought on by the COVID-19 pandemic.

"When we look back at the COVID-19 pandemic in decades to come, we will think of the challenges we all faced – the loved ones we lost, the extended isolation from our families and friends and the strain placed on our key workers," wrote Kate in the book's foreword. "But we will also remember the positives: the incredible acts of kindness, the helpers and heroes who emerged from all walks of life, and how together we adapted to a new normal."

Eagle-eyed fans of the royal family noticed a distinct tribute to her late mother-in-law, Princess Diana in her announcement post on Instagram. Around the Middleton's neck is a ruffled piece of fabric called a "pie crust collar", and it was a beloved accessory of the late Princess Di.