Prince William reportedly looked sombre and regretful during his first-ever appearance at the State Opening of Parliament on Tuesday, May 10, where he joined his father Prince Charles, and his stepmother Camilla, the Duchess of Cornwall.

Body language expert Judi James pointed at two instances that showed the Duke of Cambridge looking sad and regretful. One was during the procession when he took his place behind the Prince of Wales and the other was when he took his seat on his father's side.

She said that Prince William almost became the "invisible man" as he "tugged at his waistcoat on arrival" with his hands clasped "in the fig-leaf position in front of his torso for the entire event." He only placed his hands down on his lap once he sat down.

For Prince William, that's his historic moment to join in the State Opening of Parliament in the House of Lords at the Palace of Westminster, that's his FIRST EVER moment.

?Ohhhh... pic.twitter.com/tU2gboqAWo

— ?Sarahsecret (@sarahinroyal) May 10, 2022

Jame told The Mirror, "He walked with his hands clasped like this, suggesting a lowering of his own status and presence. His facial expression suggested sadness and regret." She added that "his polite smiles were down-turned with the lips sucked in to emphasise the idea of sadness and his frown and down-turned eyes gave a very sombre look to his body language."

Thank you Prince William for stepping up to help your Grandmother who was unable to attend today’s State Opening of Parliament & supporting your father. pic.twitter.com/4et55luvwW

— Ayramrosi ☘️ (@aryamrosi) May 10, 2022

It is unclear what led to the duke's sad look but it could be the obvious absence of Queen Elizabeth II at the State Opening of Parliament. She reportedly pulled out of the event under the advice of her doctors because of her mobility issues.

Her Majesty's throne was visibly also missing and in its place was her Imperial Crown placed on a velvet cushion. Prince Charles read the Queen's speech in his mother's absence. James noted, "Of course, the most powerful presence at this State Opening of Parliament was always going to be the missing one. Even with the Queen's throne removed the gap left looked poignant."

In contrast to Prince William, James said that Prince Charles showed "undeniable signs of nerves" at the State Opening of Parliament. She claimed that he also appeared "preoccupied with the crown that sat in front of him, gazing at it for several moments before he was given the speech to read."

State Opening of Parliament
State Opening of Parliament at the Palace of Westminster, in London. Photo: Reuters / POOL Reuters / POOL