Why do TV studios put scenic backgrounds during interviews with people not in the studio?

Whenever someone from another city or area comes on during the news or an interview, you can usually see something like an important building (White house in Washington, D.C), and there will be some sort of movement.

Why do TV studios put scenic backgrounds during interviews with people not in the studio?
it makes them look as though theyre sitting in front of a window, sometimes they really r sitting in front of a window, to tell, see if outdoor scenery changes.
Reply:yesterday l saw an author sitting in front of an obvious fake book case. lt looked like wallpaper border put one under the other. l guess they do this for effect. Doesn't "effect" me.