Well done, Aglaya! That is one of my favorites. I believe it was taken in early August of 1916, since Z. Makarov left at mid of August. Bank near Dnieper River, Heir called 'Evpatoria' - like place at South Crimea. And ones of his happier days he spent there, while visiting General Headquarters, at Mogilev. He used to rode motor - bike in fields around. Sometimes with Igor Konstantinovch he ran into the water, or sailed with little Yacht along the River during summer days.
I believe same day -- it is labeled 'seredina augusta 1916' what means 'Mid of August of 1916'. I think many photos from that period can be found in IF's private Albums.