Perspective on a FE is somewhat different. It's the same reason you see ships seeming to sink at the horizon.
Normally, if you imagine an endless flat surface, and an object right above it, then in lieu of any other influences you'd expect that as the object above the surface (keeping at a fixed altitude) moves away from you, it will appear to shrink and get closer to closer to the surface. If you could always see the object, rather than it fading out, it would seem to eventually touch the surface at a fair distance away.
Under FET, what happens (either due to 'bendy light' or atmospheric refraction, or some such law) is that the point at which the object seems to touch the flat surface comes much sooner. It looks lower than it really is.
In models with the spotlight Sun, which I'm guessing you read from the FAQ, there's only one side that's lit so it wouldn't be a small object in the distance. It doesn't get so far away it can't be seen, it just gets so far away that the underside can't be seen. Refraction/bendy light essentially stops us noticing as it starts looking like an ellipse.
As a side note though, not all models follow the kind of outline you saw in the FAQ. There are a wide array of FE models.