Meghan Markle
Meghan Markle breaks a royal protocol on her second engagement with Queen Elizabeth II. Pictured: Markle, Prince Harry and Queen Elizabeth II at the Queen's Young Leaders Awards Ceremony at Buckingham Palace on June 26, 2018 in London. Getty Images/John Stillwell

Meghan Markle may have once again broken a royal rule.

On Tuesday, the Duke and Duchess of Sussex accompanied Queen Elizabeth II for the Queen's Young Leaders Awards. Markle wore a pink Prada dress and went with glossy makeup for the event. However, many noticed that she didn't sit like a royal should.

According to Emily Hodgkin, a journalist for Daily Express, Markle sat with the Queen and Prince William for an official portrait for the event. In the photos, the new royal can be seen sitting with her legs crossed on the lefthand side of her husband. Female royals usually do not sit this way as instead, they sit in a manner that is called the duchess slant.

"Typically the 'duchess slant' is used when a lady has to sit for an extended amount of time while keeping poise and posture," Myka Meier, royal etiquette expert and founder and director of Beaumont Etiquette, told People. "It is the perfect pose for when a camera is shooting directly in front of you because by slightly slanting the knees to create a zig-zag effect when wearing a dress or skirt, your legs are angled so that the camera only shoots the sides of your legs and protects your modesty."

Meier added that the duchess slant is one of the most elegant and flattering ways to sit because it makes one's leg appear longer. To make this sitting position easier and more comfortable, the expert gave some tips.

"The key with the technique is to square your shoulders straight ahead while maintaining perfect posture," Meier said. "Keeping knees and ankles together at all times, position your legs so that you create a slant, angling your knees to the side. Hands should be folded one over the other and placed in your lap."

Markle was seen copying Kate Middleton's duchess slant when they made their first royal engagement together. However, she also had some photos where she crossed her legs. According to one expert, the Duchess of Cambridge sits more ladylike than the Duchess of Sussex.

"Her Royal Highness The Duchess of Cambridge is sitting in a correct and ladylike manner, which she would have been taught at an early age," said Grant Harrold, a former royal butler.

"This sitting posture is not only the correct and ladylike manner but is also a practical way of protecting one's modesty when wearing a dress or skirt," the etiquette expert continued. "Ladies wouldn't normally cross their legs and certainly would not cross at the knees."