Why Do They Hang Portraits in the White House?

It must be really weird to live in a house with portraits of your enemies. Imagine if every one of us were, like, showing people around your house. That's what presidents have to do. O bama had to walk down hallways looking at george w. Bush's picture. Donald trump had to sit on the toilet with the portrait of bill clinton looking down on him. I can't go wen, i'm being watched. Why did i put the picture in the bathrob? It would be cool if these portraits were alive, like an harry potter ere wouldn't that be amazing?