Here again, Google Images confirmed me that this picture was already published elsewhere: indeed, I’ve found the very same picture on some sites that sell stock photos.
This picture was taken in September 1914 and shows Belgian officers being brought to Germany (to Hannover, according to the caption written on the reverse of the picture). This picture was distributed by the Berliner Illustrations-Gesellschaft and bears the ID #1508.
Some details of this picture are interesting:
– the German soldier who leads the march holds two swords, which look different. One of them is probably a Belgian one, taken, as souvenir de guerre.
– we can notice a priest (a chaplain?) in the POWs’ group.