The iPhone Duo's inner screen hides its front camera behind the display, and early reviews say the photos it takes are poor.
It is the first under-display camera on an iPhone. The lens sits beneath the screen's pixels, so the display looks uninterrupted, but light has to pass through those pixels before it reaches the sensor. Apple said the camera records 1080p video and did not mention photo quality.
Reviewers filled that gap. Gizmodo's reviewer said the camera is 4 megapixels and described its photos as "low-res, washed out, and just not sharp at all." The same review called it unsuited to selfies and said video calls "look muddy." Marques Brownlee called the camera "very first gen" and the photo quality "trash." Reviewers did say it handles video better than photos, and that it disappears into the background during normal use, which is the point of hiding it.
There is also a workaround. One review noted that when you unfold the Duo and point it at yourself, an option moves the camera controls to the outer screen. The outer display then acts as a viewfinder for the rear camera, so you can take a selfie with it instead of the inner one.
The precedent is not encouraging. Samsung used under-display cameras on earlier foldables and dropped them because of poor image quality. Brownlee wondered whether Apple will make the same call down the line.
The trade-off is clear even from this thin set of impressions. A hidden camera gives you a cleaner screen, and a camera behind the pixels gives you a worse picture. Apple's spec sheet leans on the part that held up, video resolution, and says nothing about stills. Whether a second-generation sensor can close that gap, or whether Apple follows Samsung out of the category, is the open question for the Duo's next version.