In "Nosedive", there is a frame where a social media post from Michael Callow reads, "Just got thrown out of the zoo again :(", a joke based on Callow having intercourse with a pig in "The National Anthem".[31] Brooker has described this Easter egg as his favourite in series three.[32] Another reference to that episode is the fictional show Sea of Tranquility; in "The National Anthem", a special effects expert mentions having worked on the show, while in "Nosedive", Lacie hitchhikes with fans of the show.