When Ninotchka tells a funny story, objects on the desk change positions.
When the Russians are trying to kiss Leon, Felix Bressart's pince-nez falls off, but in the next shot it's back on his nose.
When the three Russian negotiators meet Ninotchka at the train station in Paris, the white ticket tucked into her jacket changes position from shot to shot.
When the three negotiators are drunk and Leon stands up, he at first does not have the letter in his hand, but then it appears.
When ordering cigarettes, one negotiator is beside the desk and two in front, but then it changes to two beside and one in front.
The club manager asks Leon to go to the ladies' room to retrieve Ninotchka because she "is spreading communistic propaganda". But, as a group of upset ladies files out of the ladies' room, there is a lady seated and chatting with someone across from her off-screen, relaxed and hardly "upset" over Ninotchka's attempt to radicalize her.
As she is engaged in a conversation, the lady might not have heard Ninotchka, or it's possible that she, in fact, was not upset with "communistic propaganda".
As she is engaged in a conversation, the lady might not have heard Ninotchka, or it's possible that she, in fact, was not upset with "communistic propaganda".
When Ninotchka and Leon are talking about the photograph on his desk, Leon's shadow is moving along the wall although he doesn't move.
The lettering on the bottle of goat milk Leon sends to Ninotchka is in English instead of in French.
None of the Russian characters speak with Russian accents, nor do the Parisians speak with French accents. Only the Visa Official has a slight Russian accent.
Re: Comrade Kopalski, "ski" is typically an ending for Polish names. In Russian, the name would more appropriately have been spelled "Kopalsky".
Iranoff, Buljanoff, Kopalski, and Leon could not have known that Razinin would send Ninotchka to Constantinople.
Ninotchka (actually Ninochka) is pronounced NEEN-och-ka in Russia, not Nee-NOTCH-ka. The name is an endearing form of Nina.
During the telegram/kissing scene, Iranoff refers to Bela Lugosi's Russian Commissar Razinin's name as Razin while Leon and Kopalski refer to it as Razinni, a distinctly Italian name. When it is mentioned again at the train station by Ninotchka, she again mistakenly pronounces it as Razinni. It isn't until later in the film that the correct pronunciation is used.
Knowing how incompetent Iranoff, Buljanoff, and Kopalski are, Razinin would have been sacked by his superiors for sending them to Constantinople.