The Windows Phone 8 application is designed to simulate the functionality of the Windows Phone 8 operating system on a Windows Phone 7.5 device.
In particular, Windows Phone 8 replicates the behavior of the live tiles in Microsoft’s new mobile operating system.
It allows you to preview the tile sizes of Windows Phone 8 and experiment with moving them around. However, there are no options for resizing live tiles, which is one of the big improvements in the actual operating system. This function is better replicated in W Phone 8, an application which feels more interactive than this one (though still pretty crude).