In the beginning when Clarke tries to hack the car, his device displays command lines including '\bm\04\callister\60s.custom.drivers' and '\bm04\mianolan\architecture.sys', which refer to USS Callister (2017) and Crocodile (2017) (and this episode number). The third command line is '\bm04\reddit\easter.egg.sys'.
The dog is inspired by the Boston Dynamics 'Spot'.
This episode has the lowest amount of live human characters out of all Black Mirror (2011) episodes at just three.
Charlie Brooker confirmed that it was not his intention to make the dog appear to be guarding the warehouse. Although never explained on screen, it was a war machine relic from whatever produced the post-apocalyptic world.