Playing cards with photos of 'most wanted' enemy leaders have historically been distributed to troops in wartime as an aid in identifying the target. In the world of "The Man in the High Castle," The Marshal uses this same system to identify those that the Nazis have him hunting.
In the world of "The Man in the High Castle," the Nazis are displaying respect and sensitivity to the Japanese culture by applying the practice of Feng Shui in the arrangement of the furniture during the Crown Prince and Princess' visit to the Nazi Embassy. An extensive amount of research and consultation on the part of "The Man in the High Castle" Art Department went into understanding how Japanese royals are positioned in public settings. Both modern and historical references indicated the Emperor and Empress would be seated in front of a royal screen panel.
The costume design of "The Man in The High Castle" Crown Prince and Princess was inspired by real life Crown Prince Akihito and Princess Michiko of the same era. Married in 1959, Prince Akihito and Princess Michiko ascended to the throne in 1989 when Akihito's father, Emperor Hirohito, died. The couple are Japan's current Emperor and Empress.
In the world of "The Man in the High Castle," the bounty hunter known as 'The Marshal' collects the fingers of Jews that he kills as a way of tracking his bounty to be paid by the Nazis. In reality, during the Holocaust, bounty hunters were ordinary citizens in need of funds who would be given money by the Nazis in exchange for captured Jews. Sometimes these bounty hunters would travel hundreds of miles in pursuit of their targets.
The Nazis experimented extensively on prisoners of war, Jews, and other 'unwanted' during WWII for a number of reasons, including the intention of discovering a viable 'truth serum.' Lysergic Acid Diethylamide, more commonly known as LSD, was developed shortly after the war in Europe and brought to America. Even the USA was experimenting with viable 'truth serums' since the development of the Cold War; they quickly recognized the mind-altering potential of LSD and experimented with it extensively. In the world of "The Man in the High Castle," it is the Germans who recognize the potential of LSD as a 'truth serum' and use it as part of their interrogation techniques.