Glittery glue dots - for magnets! It looks like those glass filler stones (or maybe dried resin or glue? hmmm), and glitter for the materials - No instructions, but it seems pretty simple going from the pictures.
Check out info on resin casting. You have a mold, mix the resin with a catalyst. Whatever is in the mold gets embedded in plastic. - This link doesn't include info, but it's a reminder to go check out more info on resin casting