What a great picture! I saw single soldiers posing with muskets before which I believed to be photographer props but never an entire unit. These do not resemble Prussian patterns and different models are also mixed, so I would assume they were used for exercising until equipment could be provided.
Is there any mentioning of their current situation in the writing?
There are numerous pictures of soldiers with original M71 rifles, reflecting the dramatic production shortfall during 1914 and 1915. But muskets are really far out .