I was on a Business trip to China from South Africa, we arrived in a small group to Hong Kong Via O.R.Thambo air port in JHB South Africa. we flew from Hong Kong to Shanghai , on arrival we drove from are port to the city , we stopped at a few sites to view , then arrived around 5-6pm outside the Oriental Pearl Tower. I was cloudy and was raining somewhat, but cloud was not too low, we could clearly see the tower, I took many pictures around the tower with the group and the attached photo was taken just before we entered the tower.when I took the picture , my attention was drawn to a light on the R/H side , but after taking the photo I could not see anything , thus did not worry further , some time later I was checking the pictures I took and noticed the light , however it was not until MUCH LATER when returning back to South Africa , , after loading all pictures on my Lap Top , that I was intrigued by this picture I took.I have NO explanation what is was , but when I took the picture it was there , and next thing GONE !The city was very busy , I was excited and did not pursue the subject.over the last year this photo has been on my mind and I would like to understand if any , is there a reasonable explanation for it? I do believe that we are being visited , and some how , I may have witnessed , even though very small , something unidentified.I do not believe anyone else in our small group say what I saw , but I did not discuss it with anyone else anyway.regards