Stephen Lam / Reuters

Apple is doubling down on its trend toward bigger iPhone screens, and bigger screens in general for that matter. Along with a huge new iPad Pro, Apple on Wednesday announced that its upgraded iPhone 6 models—the 6 S and the 6 S Plus—will have the same-sized screens as their counterparts announced last year.

And though iPhone purists may still bemoan the trend toward larger screens, Apple already knows these things will sell. “iPhone 6 is the most popular iPhone ever,” Apple CEO Tim Cook said onstage Wednesday. “These are the most popular phones in the world.”

Bigger screens are more than a business move, though. They also tell us what a phone actually is in 2015. To Apple, a phone is a pocketbook-held proxy for the watch it hopes you're glancing at on your wrist. Which is a cynical way of saying: Maybe if Apple makes a phone bulky enough, consumers will warm up to its sleeker, wearable counterpart. But it’s more than that.

An iPhone is for recording video, and publishing photos, and texting, and writing grocery lists, and watching Netflix, and reading the news, and scrolling through status updates, and and and... A bigger screen is, let's face it, helpful for all of those functions.

Maybe now is the time to point out that the iPhone’s dramatic shape shifting in the past year is all relative, anyway. Even the biggest iPhone seems sleek compared with Apple's new iPad Pro, which has a whopping 12.9-inch screen.

But let’s just consider the iPhone compared against itself. (Skip ahead two paragraphs if you hate numbers.) The first-ever model was a tiny beast with a curved back: It stood 4.5 inches tall, half-an-inch deep, weighed 4.8 ounces, and had a 3.5-inch screen. By the time Apple got to the iPhone 5, it had created something taller (4.87 inches) and flatter (a third of an inch); also lighter (3.95 ounces) and with a bigger, 4-inch screen.

So even though the iPhone 6 and its new sibling, the 6 S, are lighter and flatter than the original iPhone, their stature—5.44 inches tall, with a 4.7-inch screen—makes them seem huge. The iPhone 6 Plus, and now the 6 S Plus, is basically a Lincoln Towncar at 6.07 ounces and 6.22 inches tall with a 5.5-inch screen. (For further context, consider the latest Samsung Galaxy model, which lands squarely between the iPhone 6 and 6 Plus: It weighs 4.87 ounces and stands 5.65 inches tall with a 5.1-inch screen.)

The obsession over fractions of inches here speaks to the intimacy of these devices. People sleep with their iPhones under their pillows. Their expectations about iPhone specs come from muscle memory as much as they do from the ease with which the device can be slid into a pocket. For most Americans, a smartphone is often within arm’s reach. In a recent Pew survey, one-third of smartphone users said they never even turn their phones off.

Which is useful context when considering why, when Apple first unveiled its new, bigger iPhone one year ago, people flipped out. (“But what if I didn't want a bigger iPhone?I don't need a bigger iPhone.”) And why people will continue to flip out when the iPhone inevitably changes shape and size again someday. All this emotion is wrapped up in the fact that an iPhone is and remains a transformative device, while simultaneously being a device that is itself transforming. Its main feature isn’t that it is pocket-held in the same way that an iPhone’s main functionality isn’t to be a phone. (You want a real phone, go for a landline. As my colleague Ian Bogost recently put it: “A handset grew warm with use. One could hold it delicately or grasp it with worry. It could be hurled back into the cradle with anger or dangled from the cord in enticement.”)

And anyway. Apple doesn’t really want your phone stuck in your pocket. It wants your computer to be with you at all times. It wants you to be touching it, swiping it, gazing into it, asking it for directions, and redefining an entire class of objects to which it purports to belong.  

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