There are two ways to add view behind the window: 

  1. Plant some trees and bushes from the catalogue; 
  2. Use the Magic cube.

What you do is place a Magic cube right behind the window and apply a beautiful texture over it.

Check out this video to better study the process. 

We're using the Web version on that video. However, main controllers are the same for all apps, so you won't have any difficulties reproducing these steps on your device.