5 times Prince William and Kate Middleton followed in Prince Harry and Meghan Markle's footsteps

Prince Harry and Meghan Markle's PDA-filled engagement photos were taken by a celebrity photographer, Alexi Lubomirski, in December 2017.

In the photos, taken on the steps of Frogmore House in Windsor, Markle sits facing slightly away from Harry with her elbow resting on his leg and her hand on his.

Prince William and Kate Middleton also enlisted a celebrity photographer, Chris Floyd, for informal photos marking their 10th wedding anniversary in April.

The couple sat almost exactly the same way that Lubomirski posed Harry and Markle in their engagement photos.

In keeping with royal etiquette, the Duke and Duchess of Cambridge rarely show affection in public. In past anniversary photos released by Kensington Palace, they've maintained an air of formality.

Back in 2020 when Harry and Markle were still working royals, their public displays of affection and informality made them immensely popular.

They maintained near-constant contact on royal engagements, holding hands and affectionately touching each other's arms.

William and Middleton appeared to take a page from their book by increasing the amount of affection they showed each other on royal engagements.

In keeping with royal etiquette, the Duke and Duchess of Cambridge seldom show affection in public, but that seemed to undergo a shift in 2020 as Markle and Harry's popularity grew.

During a visit to Wales in January 2020, William was photographed placing a protective hand on Middleton's shoulder as they spoke to well-wishers outside the Mumbles Lifeboat Station near Swansea. And while visiting an arcade in August 2020, Middleton put her arm around William.

As they began their transition out of royal life in February 2020, Harry and Markle confirmed they would change the name of their brand so it no longer included the word "royal."

The couple had previously registered their non-profit organization as "Sussex Royal The Foundation of The Duke and Duchess of Sussex," and they created the Instagram handle @sussexroyal before resigning from the royal family.

"Given the specific UK government rules surrounding use of the word 'Royal,' it has been therefore agreed that their non-profit organization will not utilize the name 'Sussex Royal' or any other iteration of 'Royal,'" a spokesperson for the couple wrote on their website in February 2020.

A few months later in April 2020, Markle and Harry rebranded by launching a non-profit organization named Archewell after their son, Archie.

"Before SussexRoyal, came the idea of 'Arche' — the Greek word meaning 'source of action.' We connected to this concept for the charitable organization we hoped to build one day, and it became the inspiration for our son's name," the couple said in a statement obtained by Insider.

In May 2020, William and Middleton removed the word "royal" from their social media accounts as they shared more candid photos.

The couple's display names on social media were previously @KensingtonRoyal, referencing their home base at Kensington Palace. In May 2020, William and Middleton changed their social media handles to the more informal @dukeandduchessofcambridge. Fans noted that the change seemed more personal.

Their Instagram feed also became more candid, sharing photos of Middleton running with Princess Charlotte for Mother's Day, as well as Instagram versus reality-style pictures of Prince Louis for his birthday.

After stepping back from their royal positions, Harry and Markle started a Spotify podcast called Archewell Audio in December 2020.

The star-studded first episode of their podcast featured Sir Elton John, Tyler Perry, James Corden, Naomi Osaka, Stacey Abrams, Matt Haig, and a brief cameo from their son, Archie.

In May, William and Kate started a YouTube channel.

The YouTube channel will allow viewers a glimpse inside royal life.

Markle and Harry's tell-all interview with Oprah Winfrey in March included a clip of Archie running around on the beach with his parents and their dogs.

During their interview with Winfrey, Markle and Harry shared a black-and-white video of their son playing at the beach with his parents and their two dogs, Guy and Pula. Archie could be seen running around holding a stick while dressed in a cardigan.

As part of their 10th wedding anniversary, William and Middleton released a new video of them having fun on the beach with their three children.

The video showed William and Middleton spending time with their children outdoors with activities such as running through trees and roasting marshmallows, similar to Markle and Harry's clip.

Their more informal style could be part of an effort to help them appear more relatable in the wake of Harry and Markle's bombshell interview with Oprah Winfrey about their rift with Kensington Palace.