Maybe someone can draw a better visual example, but just imagine 5DN as a ramp:



So day 1 you plug in your first miner to Kano's Pool and you have started your 5ND for that miner. You don't yet have much invested in the pool so if a block is found then, you get a tiny portion of it since you haven't worked on anything. As the 5ND ramps up, each block find gives you a larger and larger amount for a payment based on your time and work you have done, along with the size of the block (due to the fees it has collected). Then, at the top, once that miner has reached the top of the 5ND ramp, you will get your fully vested payments for that miner when a block is found.

The same goes if you remove that miner. Even though it isn't contributing, it still has had the time it vested into the pool so you will get payments as it ramps down until it hits zero.

But like I said, maybe someone can make a better one and explain it better, especially if I got it wrong. I tried to keep it basic