15 minutes into the movie, you see a Russian soldier in a trench involved in dialogue holding his rifle with bayonet attached close to his face. The style of bayonet reveals that this model in the movie is one of the original designs of Mosin Nagant which were manufactured between 1891 and 1905. It is a Mosin Nagant 91/30- 7.62x54R (1891 model) . This is one of the few if not perhaps the only WW2 movie that has this antique weapon. This model were still actually in service in WW2, but rare due to it's age and lesser accuracy (550 metres)..
20 minutes into the movie, a Russian soldier in the dug-out can be seen dipping a cube of white food material into a cup of hot water and then eating it. This is a genuine food ration of the era which came as a small block of hardened/dried vegetable and grain soup wrapped in paper and was either boiled on the fire with water added, or cut into bite sized pieces and dipped into tea or hot water to soften it before being eaten when time for food preparation and to eat was limited.
In the movie, 2 men can be seen riding in an elevator both carrying a bouquet of flowers. The multi-color flowers are all the same species being Hydrangeas. These are less than a perfect gift of flowers as special preparation before putting them in a vase is required or they will barely last a day.