Who is the Mystery Man

Hello, I live in England and I found this photo in my late Uncle's posessions. My Uncle was in a PoW camp close to Falkenberg, I have no idea who the person is in the photo and my Uncle never mentioned him. I would love to know who he is and why he knew my Unlce. Any information would be helpful. I have also attached a document which gives information about my Uncle and his time in Germany. Who is the mystery man in the picture and why did my Uncle have his picture, did they become friends?