I believe that a desktop can reflect an area of a person's personality depending on how you look at it. Here is my desktop from two days ago:
http://i173.photobucket.com/albums/w76/SamBeckett94/desky.png
What does this tell you about me? Some may say 'you're a machete wielding murderer'. Certainly not. The sensible would say 'you like Friday the 13th and possible other horror movies'. Correct. There's nothing like a good laugh, which in a way is what horror movies are. Comedies are better, as they are lighter.
http://i173.photobucket.com/albums/w76/SamBeckett94/Mario.png
What does this one tell you? That I like to turn on the computer and straight away see a smile to make me smile (and there's nothing better than two mustached Italians to do that). In a nutshell, it reminds me that I'm not at work.