Lydia and Pettifleur appeared to have their stomachs cinched in the middle, causing Chyka to look wider, while Janet seemed to be the only housewife in the photo to be left untouched.
Fan favourite Chyka has since hit back at Lydia, saying she initially wasn't going to comment on the scandal but has been inundated with messages from fans.
The 52-year-old referenced a post her daughter Chessie made, saying women should support each other.
"What is the point in pulling another woman down... I'm all about positivity, empowerment and raising women up," Chyka wrote on Instagram.
"I think that's all I need to say! Thank you to everyone who has made me feel so protected and loved."
Chyka later revealed she wasn't sure why Lydia shared the 2014 photo in the first place.
"We haven't actually spoken to each other for at least four years so I'm not really sure where this came from. I think it's a really strange thing to do," Chyka told Daily Mail.
"There's so much turmoil, horror and sadness in the world at the moment - no one really wants to see this. I truly believe in being positive because that's how we will all get through - not being derogatory to another woman."
Lydia denied claims she'd edited Chyka to look wider around the stomach area, despite fans finding the original image which showed the mother-of-two looking more herself.
Chessie, a plus-sized model, came to her mother's defence after Lydia posted the image, blasting the reality star as "pathetic".
"A grown woman posted this yesterday," the 27-year-old wrote.
"Seven years on and the worst editing job I've ever seen. I laughed when I was shown [it] because it's truly the most pathetic thing I've ever seen.
"But I actually woke up incredibly mad that in 2021 a woman went out of her way to bring another woman down. Yes, it's my mother, but taking a step back from that.
"This is so high school and actively malicious, I'm truly in shock. What fiftysomething woman sits at home morphing herself to look thin and the woman next to her large?"
Chessie said she worries about Lydia's mindset and that the situation poses "serious questions" about the socialite's ego.
"Are you that desperately in need of attention and your ego stroked that you're willing to do that at another person's expense?" she wrote.
Lydia later posted an Instagram Story saying she had since taken down the controversial photo.
"Last post deleted. My apology to all. After being fat shamed I would not intentionally do that to anyone," she wrote.
It comes after followers flooded the now-deleted photo with comments calling Lydia out for the bad editing.
"I think somebody has been using the photoshop on poor Chyka," one fan commented on the Instagram photo.
"Lydia this is so rude," said another.
"Dying at the photoshop. Poor Chyka doesn't deserve an extra 47kg Lydia."
Lydia replied, vehemently refuting claims she had doctored the image.
"It's an old photo from season 2 no photoshop, I wouldn't do that after being fat shamed myself," she commented back.
But Lydia's followers weren't buying her explanation, saying everyone in the photo had been doctored except for her.
"It is definitely photoshopped. Look at Pettifleur's coat, that is now how that outfit sits. I love all these ladies but Lydia that is definitely not the original," one follower said.
"The fact you're denying it's been photoshopped is hilarious," said another.
Others pointed out that it's visible where the photo had been "blurred and distorted".
"I don't think you did it to fat shame but it's been poorly photoshopped and edited and you've given all these ladies a bad image and treated your followers like idiots by telling them it's not edited," a graphic designer commented.