Prince William represented the Queen at the State Opening of Parliament this week.
The Duke of Cambridge acted as the 96-year-old's Counsellor of State, as he followed alongside father Charles to attend the occasion.
Body language expert, Adrianne Carter, tells the Daily Star that the Duke had a visible fall in confidence at the ceremony, unlike his other public engagements.
"He is not always as confident at 'officialdom' as he is when interacting with real people."
She noted: "Charles looks like he's been ready to do this for a long time and is very natural and comfortable.
"Camilla and William looks more nervous by the way they're holding themselves and their posture."
Of the Duke, she added: "William keeps his head bowed a lot, which is a submissive way of being."
Prince William was feeling "the weight of the occasion" as he opened Parliament on the Queen's behalf alongside his father.
Earlier, body language expert Judi James noted that William felt like an 'invisible man' as he 'sadly' succumbed to his reality of having to give protocol to father.
The monarch was spotted at the Royal Windsor Horse Show yesterday
Prince Harry will soon return to the UK where he will reunite with his father King Charles
Harry's wife Meghan and their two children will not accompany him on the trip
Ryan Gosling and wife Eva Mendes share two young daughters, Esmeralda, 9, and Amada, 8
Ed Sheeran plans to celebrate a decade of 'x' album's success with anniversary edition
Based on Richard Gadd's real life story 'Baby Reindeer' encourages sexual assault survivors to speak out