Instead just apply the picture as a wallpaper. It is more nicer if it come with Polaroid. I made a Polaroid template in .PSD format. You can just simply edit and change the image. Save it as picture, and apply it as wallpaper.

Preview :

How to change with other picture?
Just go to this folder, and replace it whit any pictures.
ps: make sure you crop you image and make it smaller than polaroid border.

Download : Polaroid - PSD