Photographer and mum Heather Whitten took the photo of her husband Thomas and their son after he suffered salmonella poisoning in November 2014.
She said she was "overwhelmed" with love at the time when she snapped the shot.
However since posting the photo, she claims it has been "removed" by Facebook.
"The response to the image has been mixed, for sure," Whitten told The Huffington Post UK.
"There are so many different opinions and perspectives for just one image, it's fascinating and terrifying all at once."
On the photo she re-uploaded to Facebook, Whitten explained why it was such a powerful moment.
"Our intuition was starting to fire off that this was much more serious than just a virus," she wrote, speaking about her son being ill.
"As I sat in the shower with the two of them I was just overwhelmed with the scene in front of me. This man. This husband and partner and father. He was so patient and so loving and so strong with our tiny son in his lap.
"I stepped out and grabbed my camera and came back to snap a few images of it and, of course shared them."
Explaining her thoughts on the photo being criticised, Whitten continued: "I was taken aback by how many people missed the story or didn’t even look past the nudity to find the story.
"People were just hung up on them both being nude and being in the shower. I had crossed a line. It was too intimate. It shouldn’t be shared publicly.
"But, I disagree.
"There is nothing sexual or exploitative about this image. There aren’t even any 'private parts' showing."
Whitten said this was one of her favourite photos of her husband and her son because it shows him "at his best" as a father.
"He puts his children and family in the centre of his world and goes above and beyond to ensure that they feel loved and taken care of," she told HuffPost UK.
"Even if that means sitting in a cool shower for hours while his babe is sick all over him."
The last time Whitten posted the image, without it being removed, was on 2 May. It has had nearly 32,000 shares and more than 134,000 comments.
"Shame on Facebook, read the facts," one person commented. "Anyone can see this father was just cradling their child and it's a very soothing thing for him to do."
However others disagreed, writing: "I'm sorry but innocent or not why would any mother want to share that photo on Facebook?
"I can absolutely understand why Facebook deleted the photo. Child abuse is real and this could be taken as a perverted photo."
A spokesperson for Facebook told The Huffington Post UK: "While we can’t comment on individual cases I can confirm, on background, that the photo does not break Facebook’s guidelines.
"It was removed in error and it has now been reinstated."