Author's Note: Strange... both my competitor and I chose to use "Paint on Windows". :P
The edge of the glass plate can still seen in the upper-right corner. Some other areas have been retouched in Photoshop, to remove a reflection, hints to the contestant's identity, and so on.
This is definitely the hardest W1k challenge I've ever attempted. A lot of thought and experimentation with acrylics, laundry markers, exterior settings and so on came before this finalized piece. I hope W1k will have many more "alternate materials" illo/multimedia contests like this.
Good luck to my competitor.
Please view both our entries at full-size.