Kate Middleton
Kate Middleton's curtsy gives a glimpse about her relationship with Queen Elizabeth II. Pictured: Middleton and Queen Elizabeth II watch part of a children's sports event while visiting Vernon Park during a Diamond Jubilee visit to Nottingham on June 13, 2012 in Nottingham, England. Getty Images/Phil Noble

Kate Middleton's curtsy is very different from Meghan Markle's.

The Duchess of Cambridge and Duchess of Sussex were seen making a curtsy to the Queen last Christmas. Many noticed and agreed that Middleton did it better, perhaps because she has already mastered the act. According to a body language expert, Middleton's relationship with the Queen may have an influence in the way she pays respect to Her Majesty too.

"Kate's more relaxed curtsey involves eye contact and a broad smile that makes it a greeting ritual as much as an act of obeisance," Judi James told Express. "This could be down to practice making perfect in terms of her ability to be more relaxed and confident or it could imply a different protocol when a future Queen meets the current."

"(Kate’s) head is held straight as she steps back, keeping her weight on her straight right leg and kicking the back one out slightly rather than bending both knees and risking struggles with her balance," James continued. "Like Meghan's curtsey, Kate's looks complimentary to her husband's act of submission."

Meanwhile, former royal butler Grant Harrold noticed that Markle's curtsy was too low and she bowed her head. He also pointed out that one should keep the hands because "you're not a penguin." However, she commended Middleton's curtsy and said that it was "right."

James also pointed out the difference between Prince William and Prince Harry's greeting to the Queen. According to her, the Duke of Cambridge is less formal.

"His body position is less formal than Harry's and he seems to be grinning as he nods his head," the body language expert said.

In related news, the Duchess of Sussex will eventually have to curtsy to her sister-in-law in time when Prince William becomes the king. Middleton is set to be queen consort when her husband takes over the monarchy. However, prior to that, Middleton will have to inherit Princess Diana and Camilla Parker Bowles' titles.

Middleton will be the next Princess of Wales as this title will be given to her husband when Prince Charles becomes king. At the same time, she will also be the Duchess of Cornwall. According to Marlene Koenig, by then Middleton will be HRH The Duchess of Cornwall and Cambridge.