I get this message from Microsoft
Notes To Developer
The app’s pin to star and tpp list icon does not accurately represent the app and is a generic icon. The “pin-to-start” tile submitted in the .xap, which is different from the icon and tile images in the app metadata, must uniquely represent the app so users can associate it with your app. For information about icons and tiles in Windows apps, see http://msdn.microsoft.com/en-us/library/windowsphone/develop/hh202948(v=vs.105).aspx.
How do i set that tile?