A number of very elementary things. It gives a very intuitive visualization of twin primes, as they lie before and after highly composite numbers (which are also easily visualized), as well as a visual explanation for why the prime gaps tend to increase, as larger numbers are likely to collide with a factor. You can also use it to explain prime factors, least common multiples up to N (when the first N lines come into alignment), and the cyclical nature of factors in general. This is a creative pedagogical tool, not a breakthrough in number theory.