Vikram Pendse is talking about WP7 Splash Screen of your application and how you can customize it depending on your business scenario.
Whenever you start with new project of Windows Phone 7, By default you will get on default splash screen as JPEG format titled as “SplashScreenImage”.This is a 10KB file,Default size of this Image is 480x800 and it is always recommended to keep the same even while you customize it.