While on ITV's Good Morning Britain, Harrold said Markle bobbed too low. Harrold was on the show to talk about re-gifting etiquette when hosts Charlotte Hawkins and Kate Garroway asked about the proper way to curtsy before Queen Elizabeth II.
"What you should be doing, for a lady, is the right foot behind the left, and then it is a gentle bob," Harrold said, reports the Daily Mail. "You keep the hands in because you're not a penguin."
Harrold said Catherine, the Duchess of Cambridge, got it right, keeping her back straight and bending slightly at the knee. Markle dipped too low and shouldn't have bowed her head.
Then again, Kate has a bit more experience with this. She's been married to Prince William since 2011.
Harrold is considered "Britain's Official Etiquette Expert" as the Queen's butler and makes frequent talk show appearances there.
Markle and Prince Harry attended the Christmas Day church services at Sandringham with the rest of the Royal Family last week. The 36-year-old former Suits star wore a Sentaler camel-colored wrap coat with Stuart Weitzman over-the-knee boots and a Chloe Pixie bag.
Markle has been making regular appearances at Royal functions since she and Harry announced their engagement. On Dec. 21, she joined Kate and William at the annual pre-Christmas lunch at Buckingham palace.
Harry and Markle will tie the knot on May 19, 2018 at St. George's Chapel in Windsor Castle. She will only be the second American to join the British Royal Family, following Edward VIII's marriage to Wallis Simpson after he abdicated the throne.