Maybe it's been update, but when I clicked through just now it says:

    Xsnow is a software application that creates the appearance of snow falling on the elements of the graphical user interface of a computer system.

It animates snowfall on your screen behind and on top of your application windows. With santa and bird effects and a host of options to play with.

It kind of does in the screenshot, with the figure text stating that it is a sample of the applications output.

Fat lot of good that would be for anyone who can't see the picture for any reason. It should be stated in the text of the article.