While reciting Tim's personal details, Daisy says he has a younger sister called Katy (who used his Batman comics to decorate her go-cart). In real life Simon Pegg has a younger sister called Katy.
As of 2020, the actresses playing the twins are working as frontline nurses for the NHS.
When Tim and Daisy tell each other that in their younger days they were always Fred and Daphne when playing Scooby Doo, they are in fact both dressed exactly like the other, less cool, characters Shaggy and Velma.
When the twins say that it took them "forever, and ever, and ever" it cuts to a red image of both Daisy and Tim, these clips are taken from episode 1.4