William and Harry’s latest rift is one of many royal rifts analysed by body language expert Judi James for Express.co.uk.
She discussed the “frostiness” between the pair seen at Harry’s last event as a working royal.
He and his wife Meghan Markle attended a Commonwealth Service in March last year.
The expert claimed Prince William has perfected his royal poker face.
Judi said: “With his role as future king in mind, William has been honing the skills of the royal poker face for many years now, unlike his younger brother Harry whose body language tends to be much more openly revealing in terms of his inner feelings.”
The expert claimed it was a “brutal” response between the brothers.
Judi said: “Ignoring someone is possibly the most brutal response during a fall-out.
“It’s painful and stressful for both parties to perform because it is a totally unnatural body language state, increasing awareness of the other person and creating an irresistible urge to look at them more.
“It leads to a ripple-effect of tension for everyone in the surrounding area and it signals the fact that all communications have broken down.
“In a marriage, it’s known as the ‘Ask your father to pass the salt’ stage of a rift.
Judi told Express.co.uk Kate provided encouragement to her husband.
The Duchess appeared to be “in charge” of the choreography for the day.
Judi said: “Kate appeared to be a quiet, elegant presence with no outward displays of emotion but her subtler signals suggested she was supplying support and even a firm encouragement to her husband.
“Sitting reflectively with her hands folded while William lowered his head in a sign of grief and sadness, Kate looked like a calm and composed presence at a time when he must have needed it most.”