Thank you for your reply, Canyon. Can you please elaborate?
Why are you so certain this is not the Czar in the photo?
I have read accounts of the Czar's photographer using a block to place on the seat for the Czar when he was photographed with his large bodyguards. The Czar was self conscious of his short stature and the photographer compensated for it by raising him to make him look taller. The smaller man in the greatcoat on the left has obviously been raised and his feet don't touch the ground. The Czar would not have been in good health at the time this photo was taken, which probably would have been in late 1905 or 1906.
Are you aware of any other person that the photographer would have used that photographic device for? Would you know who this photo is of then, if it is not who I think it is?
I have four, at least, family members in this photo. My grandfather was a guard to the Czar. His hat identifies him as such and confirms what he told me.
The uniforms match the following photos.