1. I'm an avid kite flyer spending 2-3h per day flying kites, usually early morning and evening, as many do in China and Chongqing. I've been doing this for a decade.
My location was 100m south of Chaotianmen bridge, west side of the river. The general wind direction (ground and hundreds of meters up) was N to S, 2 on the beaufort scale.
2. I was looking straight up at my kite (I was doing a certain maneuver using line drag that requires the kite to be at a 90 degree angle above me). As I was doing this, the object came into my view from my behind. It was a bit (about 70-80 degrees) to my (and the kites) right side (west side).
3. When I first noticed it, I didn't think about what it was. I didn't know what it was, so I fixed my attention to it.
4. The conteurs of the object were very sharp. I estimated it to be about 6 meters or larger, 500m or higher, using my kite as reference (it's 3 meters wide and was at 200meters of altitude at the moment). The object was perfectly round but tilted and circled around a point outside its body. I'm not really sure though, the point might have been inside its body, making it a "wobble". Could have been outside. It was clearly round and coin shaped though, with a slow period around the axis of wobble. It kept circling (or wobbling) following a straight path for about 2km. After 2km, past the Chongqing Center (having skyscrapers) it stopped and decended slowly downwards with an angle to the west. At this point it was just a dot in the sky. Eventually I lost sight of it due to the skyskrapers.
All of this time I was paying attention and watching it. I did not feel too excited because I've seen another strange object at the same location a year earlier. That time it was a dark orb that had a little bit of reflection from the sun, it was extremely far up in the sky being completely stationary for at least half an hour, as long as I could see it. It wasn't a ballon because it did not follow any movements of clouds and there were different layers of clouds. It stayed put and in my sight until it got hidden by clouds.
Secondly, that was not the first time I saw something odd in the sky, the first time was in another city of china, and it was 5 years earlier. Two very large objects emerged from an altostratus cloud, circling around an axis between themselves. I got to capture them on video using my camera, but I've not uploaded those yet, will do at some time.