First, the obligatory: if you like it, Stumble the SOURCE: http://www.juanfranciscocasas.com/
This crappy little blog adds nothing. Even the Mail article actually has an interview with the artist: http://www.dailymail.co.uk/news/article-511688/Simply-birolliant--incredible-10ft-photographs-drawn-ballpoint-pen.html
Unfortunately, some people in the art world confuse effort with talent. "Look at how LONG it took to make these!" does not equal "this is great art". It doesn't even equal "this is good art". If you did visit his site, you'd find that his taste level is pretty damn low and that his work with proportion really isn't that great. And jebus, photorealism? Whatever the medium, it's SO over.
Lastly, you know -- making a photorealist image with a ballpoint pen on a piece of A4 paper? That's a challenge. Doing in larger than 3 meters? That's just wasting time -- and yes, most things will look a lot better when you reduce them (for web viewing) by a factor of 100+.