I'm an artist myself, colored pencil, technical pens, pastels, etc. The drawing appears to me electronically generated, not from classical artist materials. I'll look silly when you tell me he did it with pen and ink. \
The vertical gradient clued me in. The highlights compounded it.
That's what I meant, drawn on the computer, and not by classical methods of pen, ink, etc.
It would be interesting if you could ask him what program he's using, then tell us. I tried CORELdraw, got fairly good at it, but I wanted to be closer to the basics, so I switched to using classical art techniques, colored pencil, pen and ink, pastels, paper, all the stuff we've had for decades or hundreds of years.
I don't mean to imply one is better than the other. It's a matter of personal taste.
"Yes, I DID draw the picture with traditional materials. It was first drawn in 2H grade pencil and then gone over with a BH grade. After that I scanned the picture and then traced over it in Adobe Photoshop Elements 3.0 with a Graphire 4 WACOM tablet. After the stylized color tracing was done I just colored it and added the gradient background."