Take a look at this UI design from Mac application Bodega:

Note how they use window awning to simulate storefront, which is what that application does. It helps you discover applications for Mac, like virtual store. Even the advertisement signs are hanging up there and they wave with nice animation as you move the application window around. Nice touch.

It is unusual design but it does look good, it is fresh and you won’t confuse it with something else. What more can you ask for?