Steel Mountain, the storage facility which contains Evil Corps tape backups, is a reference to Iron Mountain, a worldwide operating company which works in records management, information destruction and data backup and recovery services.
The "message to Evil Corp" from fsociety includes a background video of the "prisoners of war parade" that took place in Donetsk on the Independence Day of Ukraine, during the War in Donbass.
Elliot (Rami Malek) says that Tyrell (Martin Wallström)'s password includes the date of Sweden's Independence Day. Sweden does not have an independence day as they have always been independent, they have "National Day" on June 6.
The network allowed this episode to run several minutes over time. To bring it in on time, the scene between Elliot and Krista (Gloria Reuben) would have to have been cut; the network was impressed with Rami Malek's performance and let the episode run long.
Another symbol in this episode are the two paintings Elliot (Rami Malek) sees outside the office of his therapist Krista Gordon (Gloria Reuben). The painting on the left is a depiction of a group of four figures in a field in front of a barn. Three of them are entering it while the other leans one on the fence contemplatively. The painting on the right depicts a similar setting but behind the barn. There are only three figures in it. Together, these paintings may illustrate the "illusion of choice" Elliot refers to in his interview. Even the idea of being a one or a zero, the title of the episode, seems to be inferred. They may also foreshadow the choices Elliot will soon have to make concerning his cooperation with fsociety and E Corp.