When you got a close-up, if you gaussian blur your BG, it mimics a wide angle lens and gives you more depth! It's less about mimicing live action, and more about giving the audience a clear place to focus. It doesn't feel right to stare at the out of focus BG details, so it draws your audience eyes right where you want them to look: at your crappy animation.
oh i guess here's the before picture to compare.
Okay back to work.