Fisk's bookkeeper is named Leland Owlsley. In the original comics this was the real name of the Daredevil supervillain known as The Owl.
Ben Urich is seen using a deck of cards to represent people and events to link crime around the city. For instance, using the "Jack" card to represent Vladimir, head of the Russian gang. At the top he places a "King" card with a question mark to symbolize the unknown head of the operation. This figure foreshadows/nods to Wilson Fisk's alias Kingpin in the comic books, and the diamond is a nod to the diamond stick-pin Kingpin wears in the comics.