Thirty one years ago with Prince William as a newborn in her arms, the Princess was in a similar dotted frock by Catherine Walker as she faced the barrage of cameras on the steps of the Lindo Wing at St Mary's Hospital.
The Duchess of Cambridge's empire line frock was a bespoke design by Jenny Packham, specifically made for her, so the similarity was probably no coincidence. Just as returning to the same hospital where William and his brother were born was a deliberate choice to honour a family tradition.
With the late Princess' iconic sapphire on her finger, similarly blowdried hair and unmistakable new mum glow, Kate reminded onlookers of the woman who would surely have been the most glamorous royal grandma ever.
Yet in many ways that is where comparisons end. Diana was just days away from her 21st birthday – so much younger and more vulnerable than Kate, who at 31 is poised and confident.
Even on Tuesday just over 24 hours after labour with hundreds more photographers than Diana faced, the Duchess seemed in control. She took a few questions, telling reporters that the whole experience had been "emotional…. any parent will know what this feeling is like".
Also quick to praise her husband, she announced to the world that the first nappy changed had been by the Duke.
William's whole attitude was one of a willingness to get down to the business of caring for his child as quickly as possible.
Prince Charles showed he was moving with the times by attending his son's birth in a break with royal protocol. Shirtsleeves rolled up and in casual attire, not a suit, his heir seemed even more modern and hands on.
He placed their as yet unnamed child in the car seat with ease that spoke of practice and whisked his young family away protectively in minutes. The whole carefully choreographed appearance in total probably lasted no more than 10 minutes.
The message was polite but clear: the Duke and Duchess had presented the royal baby, now they were off to the quiet of Kensington Palace so they could care for him.