Meet the new iPhone. Same as the old iPhone.

Late-night TV host Jimmy Kimmel conducted a remarkable experiment this past week. He sent cameras out to record people testing the new iPhone 5, which of course is not available yet. The lab rats were handed last year’s model.

“Oh, it’s way better,” one man said, holding the iPhone 4S. “Yeah, it’s nice. That’s definitely, noticeably better.”

Another mark: “It seems a little bit faster.”

“Oh my God, it feels a lot lighter,” according to a different reviewer. “Just a lot more higher quality.”

Yet another: “Colors are brighter.”

The joke was obvious: People can’t tell the difference between a new ­iPhone and an old iPhone. But underlying the gag is a more serious message about where we stand in the digital age, particularly with the era’s marquee device, which has become an appendage for hundreds of millions of people.

Farewell, innovation. Hello, iteration.

In the olden days of gadgetry — by which I mean 2007, when Steve Jobs introduced the iPhone — differences between devices from year to year could be so dramatic that buyers would often skip generations, hopeful that the next one would offer an even greater technological leap. Perhaps version 2.0 or 3.0 would remotely take out the trash.

The difference between the iPhone 3G and the iPhone 4 was huge, the most notable addition a thin, gorgeous retina display. The sun appeared brighter. The moon, too. But the distinction between the iPhone 4 and the iPhone 4S? Not much. And now the iPhone 5, a device many had been holding out for, is so similar to the iPhone 4 that people on the street can’t tell the difference.

The phone is a little thinner. Its screen is a little bigger, its battery life a little longer, its download speeds a little faster. It’s sort of like a high school athlete: a little taller each year, a little quicker, but the same basic package.

Yet this is a moment in tech as big as the iPhone’s invention.

Apple has grabbed the low-hanging fruit, settling on the essence of a design that will become as familiar as a rotary dial. The differences in future versions will become less and less appreciable. The phone itself, smarter analysts say, will become secondary to the ecosystem it connects to, and the major advances going forward will be about how the phone fits into a customer’s larger digital life.

“The future is all about the user experience through the device and not about the specs,” Forrester Research analyst Thomas Husson told me.

Apple has been setting up this transition for years, most notably with iCloud, which syncs and stores data, allowing multiple devices to use it. Jobs knew iCloud was so important to Apple’s future that, looking frail and gaunt, he summoned the energy to step on stage one last time to introduce the service last year, four months before he died.

We will also see, according to Forrester analyst Sarah Rotman Epps, more uses for the phone’s sensors. IPhones and accessories will tell us about our health (glucose levels and blood pressure, for example) and, knowing our location, will make us instantly educated shoppers, eaters and parking-space-finders. Expect newer iPhones to have the ability to control everything in our houses, even the dishwasher.