In Euclidean space, the surface area of a sphere of radius r grows as r2. The larger the physical area, the more objects of a given physical size can fit in it, and so the smaller they must be in angular size to fit in your field of view.
In a space of uniform positive curvature (like Einstein's static universe), the surface area of a sphere is sin2 r/R. As a result, past a certain point (r = ½πR, the "equator" of the universe if you imagine yourself to be at a pole), more distant objects appear larger than closer objects. An object at the antipodal point of the universe will fill your entire field of view.
In real cosmology, spatial slices are flat, but the speed of light is finite and the universe is expanding, and so a similar thing happens. With current best-fit parameters, sizes start increasing past a redshift of z ≈ 1.6, or a lookback time of around 10 billion light years. GN-z11, with a redshift of 11.09, looks as large as if it were less than 3 billion light years away, with a redshift of 0.25. If there were another galaxy of the same size and intermediate redshift along the same line of sight, it would appear as a smaller galaxy only partly obscuring GN-z11.
So the law of perspective is definitely a property of reality, and tells you something about the shape of the universe.