It's shadows, I think. Your photo appears to have been taken toward mid-day (lots of overhead light) but with a cloudy haze. Your photo doesn't show any shadows. But the other photo shows light entering from the right casting shadows. That would put the smokestack in the shade of the hill behind it. All the hills in the background appear to be in shadow. If the sun were coming from the opposite direction, the smokestack and the hills would be brighter.
