[monk_e_boy]

The buildings at the edge of the photos look warped. Like an extreme fisheye lens would do.

Airy disk affects brightness and sharpness, not warping.

You could put a camera lens where the pin hole is to negate this warping, but that defeats the point of a pin hold camera.

[cma]

Yes, it is proably more petzval field curvature than diffraction limiting: https://en.wikipedia.org/wiki/Petzval_field_curvature