The entire episode is shot and made in a way that makes it look like a 44 minute one-shot long take.
While the episode appears to be one long shot, in truth there were 31 shots used. They achieved a seamless look by using a technique called 'stitching', in which multiple shots are blended together. Sam Esmail stated that they chose this route in order to give the episode a real-time feel.
This episode takes place around 28 September 2015 based upon the Yahoo headline "NASA uncovers evidence of water on Mars."
Before the title pops up, you can see Elliot (Rami Malek) looking to the camera above him, and acknowledges the audience by saying "Do not leave me, stay on focus." Later on, Angela (Portia Doubleday) walks to one of the elevators, and behind her back, you can see Elliot passing by really fast.
When Angela (Portia Doubleday) confirms her identity after she completes her task, the passphrase call and response that they use ("Marlinspike" and "Moxie") are a reference to Moxie Marlinspike, a computer security engineer and creator of Signal, the end-to-end encrypted texting service that many characters are seen using throughout the series.