Name of the Technique.

Simplicity.
Its simple all it had is the building. And the smoke its not full of cars, planes, or people.

 The Rule of Thirds.

Its a good picture because you can see that the rule applies, because the picture is set in the points

 Lines.
The flag has lines and it has red & white.

 Balance.
The treees balance out the picture. Giving it almost like a focus.

Framing.

Its has like a frame like feature. And the building frame the other buildings.

Avoiding Mergers.

It has the trees , but it doesnt look like it growing out of them.