From the page: "It is very important that you make sure all of the stars are facing the same direction! [...] You may want to draw a dot with a food writer on the cupcake liner so that you know where to cut the cupcake so that the star is visible. If you cut at the wrong angle, it'll just be a weird red/blue blob. A delicious blob, but a blob nonetheless"
...so to get the full effect, you have to slice each cupcake in two and serve that way, I guess.