I suggest you read the Wikipedia article about Linux for a start:
http://en.wikipedia.org/wiki/Linux

Then you'll realize there is not really something as a "screenshot of Linux". If you use Linux, you can have as much eye candy on your desktop as you like or you can use it without any desktop. Unlike Windows or Mac OS X, Linux does not have any look per se. Linux is just the kernel and what you use as desktop (if any) is completely up to you.