Very nice photo.
We see to the left of the Kaiser, the commanding officer of UR 13, Oberstleutnant Wilhelm Hans von Frankenberg und Ludwigsdorf. The General officer to his right is X. Corps commander, General der Infanterie Otto von Emmich. In the rear from left to right, General à la suite, Generalmajor Oskar von Chelius, the second in command of UR 13, Major Jobst Freiherr Knigge and regimental adjutant of UR 13, Leutnant Konstantin Freiherr von Durant.
Regards
Glenn