We finally saw Elliot's tragic accident.
Perhaps the incident that led to his memory loss and hallucinations, Elliot fell out a window of his childhood home growing up. There were several references to the incident in season one, but this is the first time we actually saw it happen.
A lot more is revealed in the flashback.
While Elliot is in the hospital, you can overhear his parents arguing about paying the bills, alluding to financial troubles after Elliot's dad's store shuts down.
President Obama made a guest appearance. Sort of.
Elliot has a connection with God.
While at the hospital, the camera pans towards a pamplet that says "God's Hand In Our Hardship." This shot was not chosen randomly...
The show pulled off its most brilliant scene to date.
An E Corp executive returns to a cushy smart apartment, only to find all of her technology has turned against her. It felt like the show's messagewas contained in this one scene: all of the technology we are so reliant on will eventually turn against us. It was like a mini "Twilight Zone" episode.
Darlene has taken control of fsociety.
Darlene is an emotional wreck, and she's paranoid that whatever power fsociety has could vanish at any moment. Yet, she's also stepped in as a sort of de facto leader since Elliot went off the grid.
E Corp's influence is everywhere.
The hack caused a lot of damage to the company, but E Corp still holds a tight grip on the world. You can see the big "E" hidden in various locations throughout the episode. A convenience store in Boston accepts "E Coins," showing that the company even has its own currency.
This could all be in Elliot's head.
In season one, it was revealed that Elliot's father has been dead for a long time and thus, Elliot is an unreliable narrator. This makes it easier to look for clues to figure out how much of this show actually in Elliot's head.
There are very small hints (if you want to get really specific, look at the way certain scenes are shot). But it is still hard to distinguish reality from hallucination.