In this month's Scientific American column, I took a look at the outburst of controversy over software skeuomorphism, especially Apple's. (That strange bit of design-industry jargon comes from the Greek words skeuos, meaning tool, and morphê, meaning shape.)

A skeuomorph is a design element that's supposed to replicate the look of something that was a functional necessity in some previous incarnation of the product—such as fake woodgrain on vinyl flooring.

In software, skeuomorphs are everywhere: recycle bin icons for discarded documents, floppy-disk icons for the save button, and so on. But design critics say that Apple's recent love of skeuomorphism has gone too far.

Truth is, the average Apple customer probably doesn't care nearly as much as the design critics (and neither do I). But here are some examples cited as skeuomorphism run amok:

Switches: On the iPhone, the camera app offers a slider switch that moves between still photo mode and video recording mode. It resembles a toggle switch, like a light switch—and as a result, most people try to push the tiny button from one position to the other, which is a frustrating operation. (In truth, you can simply tap the switch to change its position, but not many people realize that.)

Bookcases: The iBooks app (for iPad and iPhone) displays your downloaded e-books as though they are sitting, cover facing out, on a wooden bookcase. It's a strange, space-inefficient, slightly disorienting design; real books on a real bookcase don't sit cover out, of course. (It's an even weirder metaphor in the Newsstand app—who puts magazines on a wooden bookcase at home?)

Sewn leather: Sometimes, you understand what Apple was going for; the green felt of Game Center is meant to represent a Las Vegas casino table, the yellow lines of the Notepad are meant to look like a legal pad. But the Find My Friends app on the iPhone has the look of sewn leather, complete with stitching. What real-world surface is it meant to suggest? Find My Friends has no analog in the physical world, so the faux leather is just bizarre.

Paper shredder: The Passbook app is designed to collect and manage your e-tickets (boarding passes and movie tickets, for example). When you've used a ticket, you tap a little trash-can icon—and then you watch an animation of the ticket going through a paper shredder. The novelty wears off quickly, it is slow, and it is not consistent with the delete functions in other Apple software.

Brushed metal: Apple's first skeuomistake has long since been fixed, but it was an omen of controversy to come. It was the QuickTime Player 4—the standard video-playback app on every Mac. Critics of the player had plenty of complaints. For example, the volume control was a weird thumbwheel peeking out of the left side of the window. Sure, you "turn down" the volume of your car radio, but on a screen? "The user is expected to make linear movements to operate a rotary control," one review observed. But the most baffling part was its margins, which looked like brushed aluminum. Who has a real-world brushed-metal TV?