HEHE I just bought this exact camera today for my daughter....... With the extra 55-200mm lens......
Cool. I've had the D3200 for about a year now and I love it. I've got the 55-300 for zoom.
Here are some photos of my phone desktop (taken with my D3200).
Firstly - the lock screen. This can be pretty much whatever you want and you can have a different image from Bing each day if you like (in Phone 7.8) but I just use this photo of a leopard which I took - with my D3200 and the 55-300.
Original photo of the leopard can be viewed here (along with the rest of my photography)
http://www.flickr.com/photos/jasonbrown2013/10271329213/
Now for the Windows Phone desktop. I just use the default Nokia blue theme but you there's a variety of colours you can use. I prefer having the black background to the white.
Just like most other Windows Phone desktops really.
And here is the bottom half.
The small tiles were first introduced in Windows Phone 8 but they were made available to Windows Phone 7 back in February when the 7.8 update was released.
And there you go. shame WP7 doesn't allow you to take screenshots, but WP8 does. There might be an app for WP7 which allows you to do it but I haven't had a look.