While walking to dinner in Shanghai, I noticed a light that at first glance seemed like a star until I detected moment relative to the tall buildings in the area. The object hoovered moving erratically but not a great distance. The longer I observed the object the more movement i detected. I stopped walking and observed the object for about 10 to 15 min capturing some cell phone pictures and a video. As I focused on the object it seemed to try to evade my observation dipping below the buildings then appearing as if peaking out at me from between the buildings in the distant foreground then coming back into full view when I captured the video until it moved off to the east behind buildings in the foreground. It was a bit windy and a high overcast in the area about 60 degrees F. The object moved very erratically vertically Up and down and horizontally left and right. It did not appear to advance or retreat to or from my position. The moment was not indicative of an aircraft, helicopter or balloon and the movement was often quick over short distance in ways not within the capability of aircraft performance. I am familiar with aircraft capabilities since I am a 747 Captain and this object performed in ways that are simply impossible as we understand. The object moved both with and into the wind and did not drift with the wind. I did have a sense that it was aware of my observation and once I started taking pictures it seemed to attempt to evade my observation and its movement became greatly increased but in magnitude, acceleration and speed. I stopped a by-passer to observe the object with me but we had a bit of a language problem since I don't know Chinese. She did see the object and appeared astonished by it.