Fewer appsBy now you’ve probably seen at least one mockup purporting to show what iOS 7 might look like. Maybe you liked it. Maybe you hated it. Maybe, like the hundreds of millions of people who own iPhones and iPads and iPod Touches, you don’t particularly care what a random designer thinks an unannounced operating system could look like. But the last thing you should do is ignore it, because it shows just how difficult it will be for Apple to leave its heavy-handed visual metaphors and glossy interface design behind.

Apple’s hardware and software designs couldn’t be further apart. Its devices, from the lowly iPod Nano to the increasingly important iPad, have all been designed with unrelenting modesty from the ethic of form serving function. The iOS software, on the other hand, has long sacrificed function for the sake of appearance, adding design metaphors and the much-dreaded skeuomorphism for their visual appeal, often at the expense of practicality. Apple’s products are like Dr. Rams and Mr. Warhol, if you will.

This is expected to change now that Jonathan Ive, Apple’s long-standing head of industrial design, has been placed in charge of the company’s human interface design as well. (This is just one example of large companies consolidating their executive teams as mobile becomes more and more important.) Ive is expected to bring some of his characteristic minimalism and restraint to iOS, with reports that this so-called “flat design” will make an appearance in — and may have delayed — iOS 7, the next version of the mobile operating system expected to debut this summer.

Enter the mockups. The trouble with the term “flat design” is that it can mean anything from “We got rid of the pool table in the Game Center app” to “iOS now looks like Windows Phone,” which is what the mockup linked above seems to have thought. And, as the New York Times notes, the so-called “flattening of design” is a trend informing the design practices of not just Apple and Microsoft, but also of Facebook, the Web, and other operating systems. It’s easy to think that Apple’s efforts, then, might resemble those other companies’.

The problem is that Apple’s software design has been good enough for most consumers for years now. Making iOS look something like that mockup, especially in one sweeping update, would simply confuse and frustrate all of the people who couldn’t care less about skeuomorphism or which Web browser they’re using. We’ve seen just how poorly this can work with Windows 8, which emphasizes Microsoft’s new, flat interface over the traditional Windows desktop users have grown accustomed to over the decades.

Ive has shown that he would rather get something right and slowly change it than introduce drastic changes all at once. Hell, even some of these small changes — like, say, switching from the 30-pin dock connector to the Lightning adaptor — are met with swift, strong criticism. Anyone expecting this to change simply because Ive is working with software instead of hardware underestimates why Apple CEO Tim Cook put Ive in control of both sides of the company in the first place.

“The face of this is the software, right? And the face of this iPad is the software,” Cook told Bloomberg Businessweek, referencing the iPhone. “So it’s saying, Jony has done a remarkable job leading our hardware design, so let’s also have Jony responsible for the software and the look and feel of the software, not the underlying architecture and so forth, but the look and feel.”

Much like the iPhone and iPad themselves, which have slowly changed over time to become the products they are today, iOS will probably be changed through a number of relatively small iterations, not a single press of the flat-design-o-matic. Apple is changing one of the most popular — and most important — operating systems on the planet, the “soul” that powers its most important products. Viewing some of these mockups should put just how monumental a task this truly is into some perspective.