I don’t have the math language to explain what’s going on here very well. It’s a diagram of the Rastrigin function, which is, ahem, “a typical example of non-linear multimodal function.” Or, if you prefer, “It is highly multimodal, but locations of the minima are regularly distributed.”
It’s a mathematical function used for optimization tests. So if you want to see how your computer model handles whatever information you’re putting into it, this function is one way to do it.
Beyond that, I get lost… but it sure is pretty.