Barbari was shocked by Facebook's response, writing on her page that "it's unbelievable" the social media giant would take down the image. She posted a follow up comment and image with the statue in a dress, saying that in the 1950s, schoolchildren used to cover up Neptune.
"Maybe Facebook would prefer the statue to be dressed again," Barbari wrote.
Facebook has not yet responded to a request for comment but issued a statement to the Guardian, apologizing for the mix up.
"Our team processes millions of advertising images each week, and in some instances we incorrectly prohibit ads. This image does not violate our ad policies. We apologize for the error and have let the advertiser know we are approving their ad," the social media firm said.
It's not the first time Facebook has been embroiled in controversy for taking down an image, even as it faces calls to crackdown harder on "fake news".
Last year, Facebook CEO Mark Zuckerberg was accused of "abusing" his power after the company took down an iconic, 1972 Pulitzer-winner photograph of the Vietnam War, which showed naked children running from a napalm attack. Facebook removed the photo claiming it broke its guidelines on nudity but later reinstated it after recognizing "the history and global importance" of the image.
Facebook says in its community standards guidelines that it restricts displays of nudity "because some audiences within our global community may be sensitive to this type of content". It says that it removes photographs of people displaying genitals or buttocks and some images of female breasts if they include the nipple. But it allows images of women breastfeeding or showing breasts with post-mastectomy scarring