What does the "over" joint and what does "look down" mean here?
The weather in Beijing is less polluted than it was 10 years ago before the opening ceremony of the Olympic Games, but the boiling hot city over which the stormy August clouds look down has been transformed in the 10 years since that spectacular event.
Source: The Irish Times
over which. I know it's a clause and takes the preposition to the front.
It means "... clouds over the city"?
What does "look down" mean?