A little correction, refresh rate and FPS are basically the exact same thing, only difference is that refresh rate has to do with the frequency crystal used for the screens, so while refresh rate is in Hz, it's the same as FPS (eg: rf of 60Hz is 60FPS). No need to separate those two. Also, while the picture supposedly shows the "difference", it's not really accurate. You can't compare 60 and 24FPS on the same screen all the time, as one of the two will actually get chopped because of round ups/downs. So you can only compare things like 30 and 60 on a 60Hz monitor (basically it needs to be dividable by the same number for both, so something like 30 and 60 in a 75Hz monitor aren't displayed properly and same goes if you are on 144 where everything needs to be at least slightly chopped distorted unless you resort to fill-ins).
Correct me if I'm wrong, but the fact that 60Hz = 60 fps is mainly because refreshing the screen at a 120Hz rate to show a 60 fps animation would be a waste of resources So it clearly strongly linked but not exactly the same.
As for the image, you're right, I should have precised that it's more a simulation of what you would see (same screen, same parameters) than actually two animations with different fps.