The promo shot for the TV costume drama series "Downton Abbey" was removed from the show's Instagram and Facebook accounts after viewers pointed out an item that clearly didn't belong in the picture.
A plastic bottle is seen on the mantel near Hugh Bonneville and Laura Carmichael in the photo. According to BBC, the bottles like this were not "in wide use in the UK until the 1960s."
BBC also writes that the show has its own expert on history and etiquette who ensures the show's historical accuracy.
The snafu was trending on Facebook Friday morning with the users all around the world pointing out the mistake and suggesting their explanations.
"Dr. WHO left it there..." user Victor Perez-Festin wrote.
Some users posted this was an advertising trick to get people on social media talking about the show. "Downton Abbey" season five premieres in the U.S. in January.