Remember, what does it represent? We've already thought about these like these really small rectangles. We're taking the sum of an infinitely, or the limit as we get an infinite number of these infinitely thin rectangles. But when we're thinking about Riemann sums, we're thinking about, okay, we have some change in x, and then you multiply it times essentially the height, which is going to be the value of the function at that point. Well, over here, you could have the same change in x, you could have the exact same change in x, and what is the height right over here? Well, that's going to be this exact height right over here. We saw that when we constructed it.