Simple. The image is masked with another image every other pixel. If you use IE, you can reveal the 2nd image by selecting the image (or just press CTRL+A). The image is a bit corrupt die to jpg compression, it works best with GIF images properly prepared. You see the flowers because they're more colourfull/contrastfull and thus mask the other image.

What is a friend? A single soul dwelling in two bodies. - Aristotle
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