A day later her future daughter-in-law shared a near-identical image with a different background, which led to fans pointing out the obvious editing.
"Why is it photoshopped, I don't understand?..." wrote one confused fan.
"Lol I can't be the only one to notice it's photoshopped tho... It most definitely is. Nicola posted the original on her page... "
"Seems like they're walking on water... Did they change the background as she has the same pic on her IG with the same pose!!" wrote another.
Last month David Beckham congratulated his son Brooklyn on his engagement.
The retired soccer star said he was "so happy" for the aspiring photographer and his wife-to-be Nicola Peltz as they announced their special news.
Taking to Instagram, he wrote: "Congratulations to these two beautiful people ... As they begin this exciting journey together we are so so happy for you guys @brooklynbeckham @nicolaannepeltz @victoriabeckham (sic)".
A source said: "Everyone is delighted for them. Brooklyn has always looked up to his parents and grandparents, who have been married for a combined 70 years, and that's what he wants. David and Victoria are thrilled. They feel he has finally met a girl who is not after him for fame or money.
"Victoria no longer needs to solely pay for a bodyguard or driver for Brooklyn, for example, because Nicola's dad Nelson is able to help take care of the security and drivers who are needed to keep them safe. Nicola and Brooklyn's parents met earlier this year. David and Victoria flew to Florida and stayed with Nelson and his wife Claudia.
"They got on really well over dinner and are in regular contact. Traditionally, of course, the father of the bride pays for the wedding - but David and Victoria will definitely want to contribute in some way. It's too early to set a date, but they're aiming for the end of next summer or early autumn."
Brooklyn and Nicola announced the happy news in sweet matching Instagram posts on the afternoon of Saturday July 11.
He wrote on Instagram: "Two weeks ago I asked my soulmate to marry me and she said yes xx I am the luckiest man in the world. I promise to be the best husband and the best daddy one day ... I love you baby xxx".