As for what it is - look carefully. Yellow is for knight, blue is for bishop, red for rook. I've never seen a graphic quite like it with which to demonstrate the importance of the centre, or paracetamol.
I found this image, along with related others, posted over at the About Chess Forum by its creator Tom Brown. The idea behind his work is linked to Nikolai Krogius's book "Psychology in Chess" (which fortunately I've not read) says Tom:
If this doesn't do something for your board vision, then I don't know what will! ... The "chess image" is introduced in the beginning of Krogius' book on chess psychology, which I am working my way through. I figured that once a guy can work with the chess images, then he'll be in good shape.Interested? Tom adds "Let me know if you get any ideas on things to make images for. I am always looking for new ideas." How about the same thing, but in pastels?
(Seriously though, congratulations to Tom on some novel & intriguing representations of relationships in chess. The whole of thread at About Chess & Tom's Blog are certainly each worth a read.)