| Used to Lie about History, Whether Made for the Purpose or Not
The movie depicts events that never occurred (unless something similar was done by the Soviet Union's NKVD before World War II). The villains in this movie are clearly Germans (there's no dialog, but lots of swastikas, death's heads, and SS runes). The (child) victims are notionally Jewish, but this is never explicit.
Morgenstern's crude concoction panders to the anti-German sentiment rampant in 1961 in Poland and the rest of Europe and the United States, and also pleads martyrdom for the Germans' victims, Jews in particular (Morgenstern was Jewish).
Ironically, most of this movie (except for its credits) was displayed continually at Los Angeles's "Museum of Tolerance" as a "documentary" probably not much promoting tolerance of Germans.
Stills from this movie have been presented in all kinds of media since 1961 as actual photographs of "real Nazi gas vans. See "http://codoh.com/library/document/3279
The victims are lovable and starkly innocent. The perpetrators are vicious and cruel, and might even be taken to derive pleasure from performing their work.
This drivel is of great interest in the latter day as prima facie demonstration of a monstrously successful propaganda campaign.