With the same fisheye lens, the lens’s projection does not really change from shot to shot. In normal use, the apparent strength of the fisheye look is mostly about what is in the frame and how it is aligned.

A fisheye bends straight lines unless they pass through the exact center of the image. So in one scene, there may be few straight lines to reveal the distortion, making the image look less “fisheye.” In another, a horizon, building edge, or other straight feature placed away from the center will make the effect look much stronger.

For aerial photos, camera angle and composition are usually the main reasons the effect seems to vary. If the horizon is centered and level, distortion can be much less obvious; if the horizon is higher or lower in the frame, it becomes more noticeable.

Subject distance is generally not the cause in drone shots. Very close subjects can show additional perspective/parallax-related effects, but that usually matters only at distances comparable to the size of the lens, so it is unlikely to explain typical aerial images.