She said: “Sophie appears to be able to wear a sustained and congruent, or authentic-looking smile on every royal engagement.
“Sophie uses some small cues and techniques that create a very individual, signature look.
“Sophie’s smile is wide but not over-performed as it only reveals the upper teeth, and the corners of her mouth are often pulled down slightly to suggest emotions like caring and empathy.”
This could also be a technique she has used to become “more popular”, Judi claimed.
She added: “A dazzling style of royal smile would entail more teeth and symmetry but Sophie’s is a little more mature and complex.
“Her cheeks are slightly rounded and her eyes are crinkled in an eye-smile that also appears to signal kindness more than just happiness and fun.
“She also has a hint of a dimple, which often makes a person popular as it tends to be a signal of frequent smiling rather than just performed or ‘flash’ social smiling.”
The Countess of Wessex has been in the Royal Family for more than 20 years.
She moved from her previous career in public relations to become a popular working royal.
She will often do this while Prince Edward takes a “low key” role.
According to the expert, these roles are ones both royals seem comfortable with.
Judi added: “Edward places his hands behind his back to suggest it’s her show, but his overall mirroring of her mood and posture shows they share like-minded thinking.”
“Sophie appears to enjoy stepping into the royal limelight but we never see any signs of vanity from her.
“One of the most telling traits as a couple though appears to be the way they appear engaged and amused by one another during conversations.”