This is a theme for the full-screen display of Kirocker Music Display, version 4 and later.
Kirocker Music Display is both a panel applet and a full-screen display to see what's you're listening to in Amarok, and control the playback.
You can download Kirocker Music Display here:
To install the theme, untar the download and just open the file (the file ending with ".kirocker-theme.tar.gz").
Alternatively, you can launch the full-screen display of Kirocker Music Display, open the "Choose Theme" window, click "Import..." and browse to the archive to install.
The background image origin and license is from Vlad Gerasimov http://www.vladstudio.com
he gives permission to use this wallpaper. :)