The episode takes place in April 1970, around the time that President Nixon gave his Address to the Nation on the Situation in Southeast Asia, which Don is seen watching in his bedroom. This means that 9 months have passed since the end of Mad Men's previous episode, Waterloo.
The $100.00 tip Roger leaves the waitress at the beginning of the episode would be equivalent to $653.91 tip in 2018 dollars.
The opening shot shows Don wearing a blue shirt - the first time he has worn anything but a white shirt with his suit at the office.
The first episode of 2015, all these episodes have been called "small finales."
The fur worn by Rainey Qualley in the opening scene and others throughout the episode was a real chinchilla coat rented by production. Because chinchilla is very fragile and does not last a long time, no actors were allowed to wear it when they weren't filming; the minute "cut" was yelled, the fur had to be taken off and handled by the costume team.