As promised by the cast beforehand, this episode contains many callbacks to the pilot episode, Winter Is Coming (2011): a queen and a king arrive at Winterfell while a young child (Bran and an unnamed boy) climbs up for a better view; Arya is with the guards watching both arrivals rather than with the rest of the Starks; among the retinue is an incestuous couple (Jaime and Cersei; Jon and Daenerys, although they don't know it yet); both Catelyn and Jon ask Sansa "where's Arya?", and her answer changes from a silent shrug to "Lurking somewhere"; the monarch is welcomed with the words "Winterfell is yours, Your Grace"; Sam and Jon's conversation about Lyanna in the crypts of Winterfell mirrors Ned and Robert's conversation there; the Night's Watch finds a child's corpse and severed limbs forming a pattern; the ending scene is an interaction between Jaime and Bran.
Jon becomes the second person in the series to ride a dragon by himself when he mounts Rhaegal, who is named after Daenerys' brother and his true father Rhaegar. This may have been foreshadowed in Beyond the Wall (2017), when Jon was the only member of the party who didn't escape on Drogon; in the fifth novel, "A Dance with Dragons", it is stated that "no rider ever flew two dragons".
There are many musical call-backs to the pilot episode Winter Is Coming (2011) in this episode: the music that plays when Jon and Daenerys arrive is the same as when Robert arrives; the music that plays when Jaime sees Bran is the same music that played when Jaime pushed Bran out of the tower.
In The Kingsroad (2011), as Jon departed Winterfell, he asked Ned about his mother; Ned replied, "The next time we see each other, we'll talk about your mother. I promise". In this episode, Jon is looking up at Ned's statue in the crypt beneath Winterfell as Sam comes in, and answers Jon's question. When Sam explains that Ned promised Jon's mother Lyanna that he would always protect her son, Lyanna's statue appears behind Jon, out of focus.
The first time Jon and Arya share a scene since The Kingsroad (2011). The reunion is clearly more heartfelt than the one she had with Sansa in The Spoils of War (2017); it has already been established that Arya and Sansa have a strained relationship due to their widely differing personalities, while the novels and HBO's Viewers Guide confirm that Arya has always been much closer to Jon, as both felt like outsiders: Jon as a bastard, and Arya as a tomboy. When Jon reassures Daenerys that Sansa didn't like him either when they grew up, it is a reference to Sansa apologizing in Book of the Stranger (2016) for being awful to him. This is an invention of the show: the books never mention that Sansa mistreated Jon, only that they didn't interact much during childhood.
Dave Hill: the writer of this episode has a cameo as the Greyjoy guard whom Theon kills with an axe right before rescuing Yara. Hill had to spend four and a half hours in make up to apply the prosthetic injury that made him virtually unrecognizable.
Rob McElhenney: The ironborn guard who gets shot through the eye when Theon rescues Yara is played by one of the creators and stars of It's Always Sunny in Philadelphia (2005). Game of Thrones creators David Benioff and D.B. Weiss wrote the episode Flowers for Charlie (2013) of his show, and made guest appearances in The Gang Goes to a Water Park (2017).
Martin Starr: The second ironborn guard who gets killed by an arrow through the forehead when Theon rescues Yara. Starr is part of the cast of another HBO show, Silicon Valley (2014), and a friend of showrunners David Benioff and D.B. Weiss.