This Reddit thread shows a slight “bend”[1]. I’m distinguishing between an intentional allowance for bending vs a deformation that shows up later due to folding. But this is obviously splitting hairs because whatever we want to call it, the thing people don’t like about folding phones is the bend in the display where the fold occurs. And it looks like the Duo has that. Maybe the optical and technical tricks Apple has thrown at the problem will make the slight bend so inconspicuous as to be a non-issue. To me, telling that story is more impressive than claiming it doesn’t exist.
[1] https://www.reddit.com/r/pics/s/URdlaUpIrH