The default tile images also define the sizes that the tile supports. Tiles are available in two sizes: square or wide. All apps must support a square tile, but an app can also support a wide tile. If an app doesn’t provide a wide logo image for the default tile, the app tile cannot be resized to a wide tile, which means that it cannot receive a wide tile notification. If the app includes a wide logo image, Windows shows the tile in its wide format by default.
Então, basicamente, cabe ao desenvolvedor do aplicativo implementar esse modo de ladrilho grande opcional.