One quirk of Chinese apartment hunting is that the ‘property sizes’ are listed including communal spaces such as hallways, atrium, bike storage – as a rule of thumb only 75% of this is private space. That ‘200m square’ apartment you are looking at? Is in fact closer to 150.
In a different culture I’d assume the difference would be over-ambitious agents trying to pull a fast one, but here its a reflection of how (differently to a westerner) locals think about space.