Oh, this is even more interesting after looking into it (see this diagram from another site): https://www.dpreview.com/news/7542036825/french-startup-is-p...

The curvature goes in the opposite direction of what I would have thought. I would've thought the orientation of the curve was in the sense of maintaining a "constant radius" from the end of the lens stack. (exit pupil?) I.e. the curve helps bring in the distant parts of the sensor closer and more orthogonal to the light rays.

But the diagram shows the opposite kind of curve! That makes even less intuitive sense to me.

(I can't imagine someone not involved with the company creating this diagram, or it being so wrong and not being caught by some review process? I figure the diagram is legit? Someone drawing ray tracing level details would get it so wrong?)