Ward mentions "Strucker." Baron Von Strucker is one of Hydra's heads and at the time that this episode takes place in possession of Loki's staff. He made his debut in the mid-credits scene in Captain America: The Winter Soldier (2014) and returns in Avengers: Age of Ultron (2015).
In the comics, Cameron Klein is the grandson of Stanley Klein, one of the Howling Commandos.
"Chasing windmills" is a reference to Don Quixote.
The aerial shot used for the town in upstate New York is the same aerial shot that is used for Rosewood on Pretty Little Liars (2010).
"The Writing on the Wall" originally aired on ABC on November 11, 2014, and according to Nielsen Media Research, was watched by 4.27 million viewers.