Speaking to Express.co.uk, she stated: “This looks like such a joyful and even indulgent relationship between the Queen and her grandchild Zara.
“It is perhaps made more relaxed because Zara is not an official member of ‘The Firm’ and so can see and treat the Queen purely as her grandmother, rather than also being her boss.”
As Zara does not work on behalf of the Queen, the monarch may be able to be more relaxed than with others in the family.
The coronavirus pandemic means the royals have not been seen out together recently.
During previous outings, however, Judi claimed they showed a very close relationship.
She suggested the Queen appeared to enjoy Zara’s “spontaneous” body language.
“There are three key body language signals defining the strong bonds of affection here, their proximity, their touch rituals and their mirroring,” Judi continued.
“Zara is probably the most openly tactile and spontaneous-looking member of the Royal Family as well as being the most good-humoured-looking one.
“Both those qualities seem to have a very positive effect on the Queen, allowing her to be more openly demonstrative than she is seen to be in public with most of her other relatives.”
When seen together at the races, Judi suggested they had a shared sense of fun and affection.
She added: “Zara’s body language looks more like that of a happy, playful child here as she leans back with both hands on the balcony in front of her.
“This, and the very affectionate-looking smile she aims at her grandmother, look like an invitation to share the fun.
“The Queen reciprocates, with a broad, eye-wrinkling smile that involves an upper and lower teeth display.
“In another appearance, Zara seems to mimic the body language of a small child again here, holding her arms out in an intentional gesture to request a hug.
“Her over-long sleeves and her curled fingers look very childlike and her raised chin and adoring smile registers genuine pleasure at greeting her granny.
“The Queen’s out-stretched hand shows she’s reciprocating the greeting gesture and her rounded-cheek smile and eye contact suggest a strong, happy connection between the two women.”