After years of leaks, Apple has finally announced their foldable, the iPhone Duo. It’s already incredibly popular, and I have to hand it to them. I never thought Apple would do this. Now-former CEO Tim Cook was the master of market segmentation. They never put a touchscreen—a relatively common feature on Windows laptops—on the Mac because then they couldn’t sell you a MacBook and an iPad Pro. And I was sure they would never make a foldable because then they couldn’t sell you an iPhone and an iPad Mini. But they proved me wrong, and all it took was a foldable that costs as much as an iPhone Pro and an iPad Mini.
But now the iPhone Duo is here. It exists. And they almost got it right.
Almost. But not quite.
It’s telling that CEO John Ternus’s introduction to the iPhone Duo went over the shortcomings of previous foldable phones: the idea that they were basically two flagship slab phones stuck together along the long axis, so that when they open, they’re basically a square. He pointed out that a square(ish) aspect ratio is a jack-of-all-trades but master of none. It’s not particularly good at anything. It’s too wide for portrait text, and it’s too tall for landscape video. He was absolutely right.
The problem is, the iPhone Duo makes the same compromise. It doesn’t go as far, but the aspect ratios for the outer and inner screens of the iPhone Duo aren’t particularly well suited for anything. They made a big deal during the presentation of pointing out that the iPhone Duo has the same aspect ratios whether it’s open or closed. The way they phrased it was 1.4:1, which is accurate, but we’re used to discussing aspect ratios in whole numbers, so let’s say the aspect ratio for the iPhone Duo cover screen is 5:7. Then you open it up, and the landscape inner screen is 7:5. Or if you turn it 90°, it’s the exact same 5:7 as the cover screen, which is elegant from a mathematics point of view. I’m sure it made some of the hardware designers at Apple feel warm and comfy in their beds at night, but 5:7 still isn’t particularly good at anything. It’s too tall for video and too wide for text, just like the Pixel Pro Fold, just like the Galaxy Z Fold Ultra. They still missed the mark.
The core concept with foldables is that each screen configuration—closed, open portrait, open landscape—serves different purposes. Each should be optimized to that purpose, and you don’t do that through compromises. Consider what Samsung did with the Z Fold 8. The outer screen is the same 10:16 aspect ratio as the original Galaxy Note (and despite everyone bitching about how small it is, slightly bigger at 5.5 inches than the Note’s 5.3). This is a tried and true aspect ratio for a phone, and when the device is closed, it’s used as a phone. Open the Z Fold 8 and it’s 4:3 at 7.6 inches. 4:3 is the same aspect ratio as decades of SDTV content, the same shape as CRT monitors, the same shape as the original iPads. It’s the ideal aspect ratio for a tablet. Turn the device 90 degrees to portrait orientation and it’s 3:4, which is, again, ideal for long form reading and many productivity apps. And if you go back to landscape and split screen two apps side by side, both are 2:3, the same aspect ratio as Surface tablets and the original iPhone (which was 320x480 pixels, multiples of the 160 pixels from the original Palm Pilot).
Each “pose,” to use Apple’s terminology, has an ideal shape, and 5:7 is ideal for none of them. And the irony is, Apple knows this. That’s why they’re trying to fill up that wasted space on the cover screen by moving the dock and the status indicators off to the side. They compromised the design in the name of aesthetic consistency.
But as Steve Jobs once said, “Design is how it’s used.” By Steve’s own standard, this is exactly the wrong compromise. (Given that the iPhone Duo will also support the Apple Pencil and Steve also said, “If you see a stylus, they blew it,” the writing was probably on the wall anyway.)
And you can see it in the software, too. I saw an interview where Apple Marketing SVP Greg “Jaws” Jozwiak was crowing about how “only Apple” could have done all the neat little software touches that power the iPhone Duo. I would say only post-Steve Apple would be dumb enough to do all the nonstandard crap that the Duo requires. If they were sensible, the Duo would have been a real duo: an iPhone running iOS when closed, then an iPad running the iOS superset iPadOS when open. You get all the UI features you need in both modes for free, and developers already support the device.
Instead, the iPhone Duo is a computing mullet, and the shape forces the software to adapt. Closed, it has to run a custom version of iOS, and Overcast developer Marco Arment lamented on his podcast that supporting the new vertical toolbars, rotation, side safe zones and unpredictable screen geometry will take a ton of work for third party developers, and require a version of Xcode that wasn’t even available after the announcement, with Apple saying it would be available “later this month.” Open, the device still doesn’t run iPadOS, and thus isn’t really an iPad. It’s an iPad-like iPhone, where some of the software optimizations for iPads carry over, but a lot of them don’t. It doesn’t support freeform windowing or Stage Manager, and essentially, if you consider iOS and iPadOS to be different platforms, the iPhone Duo gives developers a whole new platform to support in their apps.
So in the interest of being “different,” Apple has compromised both the hardware and software of the iPhone Duo. Apple gave us a foldable whose two screens beautifully match each other, but neither matches what you actually want to do with it.

