Members of the Ethiopian nostalgic community were as baffled as I was. One option raised, given the name “Mekonen” on the picture, was Mekonen Loewi (or Mekonen Gobaw), a Faitlovitch student sent to London. Mekonen was a nephew of Taamrat Emmanuel, one of Faitlovitch first students – who was the head of the Jewish school in Addis Ababa . Loewy reportedly suffered in London (many of the students suffered from the weather, the different customs, unknown diseases etc.). After returning to Ethiopia, he became a teacher in the Jewish school but in 1937 he killed an Italian officer (perhaps as part of the resistance to the Italian occupation). He joined the partisans outside the capital and last thing known about his fate, was that he was killed in the countryside in 1940. It is possible that this is the person, although Mekonen was not known to have been in Germany.
Others did live and study in Germany. Yona Bogale who was already mentioned before, but also Hailu Desta (or Elazar Desta, as he was known by his Hebrew name). Desta planned at first to study medicine, but later studied governance . Here is a picture of him posing in Berlin with a fellow Jewish student from Ethiopia (maybe, not definitely, Menase Yosef , some claim it is Abera Getahun).