The Princess of Wales made her now signature gesture at the Scottish Coronation that speaks volumes about her bond with Prince William, a body language expert has said.
The pair joined the monarch and Queen Camilla at St Giles Cathedral in Edinburgh where the King was presented with the Honours of Scotland – the country's crown jewels – during a service of thanksgiving and dedication at St Giles' Cathedral.
Kate looked stunning in a Catherine Walker coat dress she's worn several times - including at Easter this year, an intricate Philip Treacy hat and a necklace from the late Queen's collection. William wore his RAF No.1 Uniform with his Order of the Thistle mantle.
The couple, known as the Duke and Duchess of Rothesay in Scotland, took part in the procession into and out of the cathedral and sat alongside Charles and Camilla as they enjoyed the rousing musical performances and readings.
While afterwards they travelled back to the Palace of Holyroodhouse where they stood alongside the King and Queen to watch an RAF flypast by the Red Arrows.
Here, they could be seen chatting among themselves as they waited for the planes to roar overhead.
And according to body language expert Judi James, this moment proved telling - and showed a major difference between the couples.
She told the Mirror: "During the flypast in particular, you could see the contrast in the way William and Kate communicate vs Charles and Camilla.
"The King and Queen are more like a ventriloquist act, both muttering asides to the other in a way that doesn't look like real conversation but the ability to mutter may feel comforting for them both at events like this.
"They often overlap in their speech, which again suggests its a mutual support and comfort tool rather than a way of conversing verbally. There is no eye contact.
"William and Kate always show signals of attentive listening to each other and here they did their signature ritual of adding either touch or truncated touch to communicate with both words and non-verbal gestures that show emotion.
"Kate even did her now signature bum-pat gesture and the couple tend to use eye contact and exchange smiles as they speak."
Meanwhile Judi also noted that this ceremony appeared to much more relaxed than the Coronation at Westminster Abbey in May - with the King appearing much less tense and anxious.
She added: "This appeared to be a more relaxed ceremony for Charles, who shared the spotlight almost evenly with Camilla, William and Kate, meaning his body language projected less of the ongoing signals of tension and anxiety than at his actual coronation and he wore a warm, beaming smile most of the time.
"He did appear to fuss and fret over Camilla this time though and when he did drop the smile and adopt a wary frown with his signature steepled brows, it was when he was turning back in concern to see her get safely in and out of their car or to move to her seat, which was when he also used some of the rapid hand-flicking gestures that tend to signal royal impatience.
"His concern seemed justified as Camilla did appear nervous. Unlike Kate she lacked the ability to perform a pose of stillness during the service and her constant patting of her hair or the white plume of her hat were self-checking rituals that hinted at ongoing inner anxiety."
