Downton Abbey promotional picture for fifth series, with modern bottle of water on mantelpiece. Photograph: @downtonabbey/PA

A promotional picture for the new series of Downton Abbey caused an online sensation when a sharp-eyed fan of the show noticed the very modern bottle of water on the mantelpiece behind Hugh Bonneville and Laura Carmichael.

Downton Abbey in hot water over bottle blooper | Television & radio | theguardian.com.