I have been experimenting with the Nokia 8 camera this weekend. When videoing at 1080p it seems to be using nearest neighbour interpolation. I recorded a hockey match and the almost horizontal distant poles of the goal cross bars appeared and disappeared rapidly as the camera moved. I wonder if internally 2160 lines are being sampled and every other one is being discarded to make the recording.
The photos have similar odd issues. If you compare the field of view left to right of a landscape shot in 4:3 and 16:9 at maximum resolutions (4160 v 3840 pixels) you'd expect the 16:9 shot to have slightly less in (take two photos and compare objects at the far left and right to see this). However the 16:9 image has slightly more in but spread over fewer pixels left to right. This means there can't be a 1:1 correspondence between camera sensor pixels and final image pixels. Whatever interpolation scheme is being used will be artificially softening the image.