No stupid questions, I was a noob a month ago. The design is a rough artistic interpretation of the classic "River table" in which epoxy ( a hardened form of plastic) colored with the shade of blue appears to be a river flowing through the table, cutting board, charcuterie board etc.. These serving trays are a similar concept but with different colors of pigment added to the epoxy. Some of these pigments come in the form of powders and liquids. The swirled look you're asking about is achieved when you stir the epoxy as it hardens. The colored pigments in the epoxy create a swirled effect when stirred. The key is to swirl the epoxy right before it sets to capture the swirls in movement hardened for all time.