How the hell d'you visualise something like that? Incredible stuff that some people can do...fortunately I never cease to be amazed at what the human brain is capable of. However...for portraits...I still think this takes some beating http://www.snotr.com/video/2925/Crazy_Painting

This takes almost no skill except a little accuracy in assembling the thing. Pixelate a photo to a certain low resolution with something like Photoshop, then analyze each pixel for brightness level and done.
It looks cool, but it's nothing compared to what real artists can do with a pen or a brush.

#2 Is your glass half empty or just EMPTY

#2 that's what makes art, everyone as a definition, everyone is touched by something should it be book, sculpture, music, painting or pixelated-photos-made-in-chopsticks.
Just imagine the impressionists in their time. Some of them were treated as fool but now it's noticed as a major part of painting history.
That's the magic of art, it's not what it looks like, or how you do it but it's what it expressed to you, what it inspires you.
Now let's look back a little ans look at the classical music. For many, Mozart was a crazy man in his beginnings compared to what music was (crazy rhythmics, unappropriated subjects, etc) but now we treat him as a reference in classical music. and certainly some people where thinking that he was talentless in this time.
Now you can be touched by how it's made or by the result or only why it is made. It's your choice to make

Very clever!