This photo was taken at the time of the German occupation of East Africa as Deutsch Ostafrika (1885-1918). The original caption was "Natives - Resting from fieldwork a Maasai woman feeds child". The reference to "fieldwork" is odd, as it would seem to imply that the woman was engaged in agriculture, which was highly unlikely unless the Germans were engaged in some form of forced labour. Any more information or suggestions about this image would be welcome.
Credit: photo taken from the Frankfurt University Photographic Archive (image reference 005-1111-12).