It is obvious that if you correctly add pieces of something like this to a viscous medium (so that the pieces are on the surface of the medium), you will get a viscous material with a visually observable diffraction effect:
https://bartovation.com/product/other-lab-supplies/diffracti...
The other thing is unclear:
Why gnaw on diffraction sheets?
Will this make chocolate taste better? Will this improve your health? It's all very exciting and mysterious.