Kate Middleton and Prince William’s have recently

“Their mask-wearing will also have had an impact though. We can see William using far more illustrative gestures to make his points as clearly as possible.

“He is miming a gesture as he talks to Kate and she responds with some attentive face-watching.”

However Judi also added that this is a rare gesture for any members of the Royal Family, showing that they have become more affectionate in public.

She said: “It looks spontaneous and it is a rare gesture for royal couples, including these two, who will normally keep a slightly more formal distance during official visits.

Judi added: “This professional ‘parting of the ways’ appears to have increased their intimacy signals when they are together, though.

“Like any couple with growing and changing careers they also seem to be using some stronger face-checking signals, too.

“This is a normal feature of role-changing relationships, where even a long-term married couple will increase their mood and thought-reading techniques to tune in to one another as frequently as possible rather than taking one another for granted.”

Looking at another photo of the pair wearing face masks while attending a surprise visit to Beigel Bake back in September, Judi explained that Kate looks confident.

She said: “William’s intense face-watching here is also important as a social signal.

“Kate’s confidence has rocketed recently, as have her status signals in the royal Firm.

“By using these active listening signals as his wife speaks, with a strong eye-gaze and puckered brows, William signals strong respect for her and her message.”