The Princess of Wales Kate Middleton is often praised for her poise in public, and has always followed royal etiquette - whether it's adhering to the diamond ban or ensuring the rules aren't broken at events.
In fact, it has been reported that Kate cemented her future role as Queen during her 2007 break-up with Prince William, as Palace insiders noted that 'she was so stoic' and 'handled herself so well' in the face of press intrusion.
The Princess is often praised for appearing calm and collected whenever she attends official royal engagements, and while they rarely engage in PDA the sweet subtle moments between her and her husband, Prince William, never go unnoticed by fans.
But according to one body language expert, there was an occasion when Kate was unable to hide her anger for the Prince of Wales.
Expert Judi James has claimed that during the couple's time in Warsaw in 2017, the Princess appeared particularly 'stressed'. At the time, they were visiting the Orangery, Lazienki Park in honour of the late Queen Elizabeth II's birthday.
Judi James the Express: "When we see a photo of a royal looking angry or stressed it can often be a body language 'flash', i.e. a very fleeting facial expression that has been taken out of context.
"When we see the whole footage the message can be completely different, especially if it’s a royal like Kate, who is normally known for her pitch-perfect social smiles that she can keep in place without looking strained or inauthentic for long periods of time."
According to James, Kate is considered to be an 'accomplished masker', continuing: "Unlike Diana, whose facial expressions could show powerfully fluctuating emotional states, Kate is an accomplished masker, meaning she does her job in exactly the way she is expected to, without any flicker of negative emotions on her face."
On this occasion, however, Kate's 'unsmiling facial expression looked shocking' and James also claims that there are several photos of her 'throwing William some pointed looks while he tried to remain neutral, with a faint, polite, closed lip smile of what looked like regret or awkwardness.'
At the time, her unusually cool demeanour was noted by royal fans. However, it led many people to consider her to be more 'relatable', showing that royals have off-days too.
