Chess Board Optical Illusion

Here is an excellent optical illusion photograph taken by Alain db of the Konica Minolta Users group on PBase.

This is an actual photograph not a digital/photoshop manipulation. The best that I can tell is the only thing done to this image was to convert it to Black & White. This photograph was awarded 1st place in Minolta Challenge #16 on PBase.

How do you think it was done?

Could a magnet be holding the King to the side of that raised block?

IdeaOnBlack
Copyright 2004 Alain db
Used w/permission

Still not sure how this photo was taken?

Alain was kind enough to provide an inside look in color with a slightly different lighting so you can tell without a doubt how it was accomplished.