Playboy Playmate Dani Mathers found herself in the headlines last week, but for once it wasn’t about her body; it was about someone else’s.

The model shared a photo of a woman undressing in her LA gym’s changeroom on Snapchat, captioning the image, “If I can’t unsee this then you can’t either.”

Whether it was her intention or not — she’s claimed it was supposed to be a private message to a friend, not part of her public ‘story’ — Mathers’ nasty post reached thousands of people and was met with a swift and strong backlash.

Mathers' Snapchat story, censored. Image: Twitter

While the 29-year-old has since been banned from the gym, reported to local police and lost professional roles — and rightly so — the cruelty of her attempt to body shame a stranger in such a public way has stuck with women around the world.

Now, they're challenging Mathers to "unsee" their bodies.

The movement was sparked when Florida mum Christine Blackmon posted a defiant open letter to Mathers on Facebook, accompanied by a photo of herself posing playfully in just underwear, a headband and sneakers.

In the post, shared to the Delicate Flowers page on Sunday, Blackmon explained the photo had been snapped by her husband while she was changing out of her scrubs.

"Later, I saw the picture and begged him to delete it. I hated it, all I saw was lumps and bumps. He simply smiled and softly said, 'I think it's beautiful'. So I let him keep it," she wrote.

How many of us have a photo like that?

Blackmon then addressed Mathers directly, introducing her to her body in all its "lumpy, bumpy glory".

"Here's the deal. You may have been a Playboy model but not all of us workout to be 'hot'. Some of us work out simply to honour the bodies we were given. That's all that woman was trying to do and you violated her," she said, referencing the stranger in the model's Snapchat image.

Watch: The trailer for new body positivity film Embrace. (Post continues after video.)

"Shame on you. I bet I could get 100s of women to post their beautiful bodies and regardless of size, shape or colour, they will ALL be more beautiful than the ugliness you showed in that post. #UnSeeTHIS."

Blackmon admits to Cosmopolitan she didn't expect her post to go viral, but it's amassed more than 40,000 likes, 5000 shares and 2000 comments.

What's even more wonderful is that it's prompted other women to put their own supposedly 'imperfect' bodies out there for the world to see.

There's this post from Candy, wearing a colostomy bag on holiday in Hawaii:

And this one from Tenesa, who refuses to hide her scars and stretch marks.

And this one from Amber, who's determined for her daughters not to feel bad about their bodies.

It's seriously heart-warming stuff, so head over to the comments section and take a look for yourself.

While it was addressed to Dani Mathers, Blackmon says her post was really dedicated to women who have been made to feel bad or self-conscious about their appearance.

"I did it for all the women who've come up to me and said 'Oh my gosh, you're right. I need to not be afraid to go to the beach with my kids because I'm afraid of what I'm gonna look like," she explained to Cosmopolitan.

"I'm not super confident, but I've got an amazing network of people that rally behind me. That was the whole point of this, that was what upset me about Dani. She broke that code. We're supposed to be there and lift each other up, not be in there with a baseball bat, beating each other down."

Featured images: Snapchat/Facebook