Earlier quoted context omitted.
An interesting difference between your photos and the renditions linked here is that the buildings in yours are black silhouettes, while the ones here are fairly well lit up. That's the first thing that stuck out at me: if there is no light pollution, what is lighting the foreground buildings? If you look at the Hong Kong photo, for example, it looks like there is a ton of light pollution: all the buildings, plus the…
On a clear night without light pollution stars provide decent illumination. However, those photo's where clearly Photoshopped.
That's pretty much what the entire article was about. :)