For most of my life, I’ve been a single screen kind of guy. I spent the vast majority of the last several years working from a 13-inch MacBook. When I did eventually add a 27-inch Cinema Display to the mix, it took at least two weeks before I was willing to finally stop piling all my windows into roughly the same amount of space as that MacBook screen.
Unsurprisingly, I adjusted. iTunes migrated to the MacBook screen, while I arranged my most frequently used apps—Mail, Safari, Adium, my Campfire client—on the larger display. No longer did it require repeated invocations of Command-Tab every time I wanted to check something in my Web browser while composing an article in BBEdit. I grew fond of my multiple displays, embraced their ability to help me do my work more efficiently.
And then came Lion. Lion, with its easy-to-swipe spaces and full-screen mode apps. Lion, with its apparent “Who the what now?” approach to multiple monitors.
Multiple monitors have long seemed like an afterthought to Apple. The original Mac—and most of the models that immediately followed it—had built-in screens. So did arguably Apple’s most famous model, the iMac. Most of the computers the company sells these days are laptops with their own built-in displays. And now, with the focus on iOS devices like the iPad and the iPhone, the company seems to see secondary displays as vestigial organs, lumping their users in the same category as those power users longingly waiting for an update to the Mac Pro.
On the one hand, I think Apple is looking forward and seeing a future in which we’re more likely to use multiple devices with single displays than single devices with multiple displays; on the other, the company still sells a pretty darn attractive display that seems like it was separated at birth from the MacBook Air.
While I may be a relatively recent convert to the dual-display lifestyle, they say that there are none more zealous. And though Lion’s embrace of multiple monitors is paltry, Apple has an opportunity to reinvigorate the capability with Mountain Lion, if only it chooses to do so.
Lion’s dirty linen
What’s so bad about Lion’s multiple monitor support? In some ways it’s no better or worse than previous incarnations of OS X. You have a choice to mirror the screen or extend the desktop, and the freedom to choose which monitor has the menu bar, and how the two monitors are arranged. Simple enough.
But there’s a real problem with Lion and multiple monitors, and its name is full-screen mode. Full-screen mode’s goal is to remove distractions, let you focus on a single app at a time. And, boy does it work—probably a bit too well, in some cases.
On my 11-inch MacBook Air, full-screen mode is actually pretty handy. I can put Mail, or BusyCal, or iTunes into full-screen, not only avoiding cluttering up the small screen with a bevy of overlapping windows, but also making them easily accessible with a simple swipe on the trackpad. There are disadvantages, too, of course—try composing a message in Mail’s full-screen mode while referring to another Mail message, and you’ll see what I mean—but the feature has its utility.
But move the same feature to my desktop, a 21.5-inch iMac hooked up to that 27-inch display, and full-screen mode for most apps becomes laughable. Not only because a huge screen like the 27-inch can easily display multiple full-sized windows with little problem, but also because if you full-screen an app on one display, this is what you see, by default.

I sure hope you like that linen pattern that Apple seems to be using everywhere now, because if you’re using multiple monitors, you’re going to get an eyeful of it.
Now, if the app has multiple windows, you can size a second window to fit on your secondary display, but in many ways that seems antithetical to Apple’s goal of a single-window, iOS-esque experience in full-screen. Again, Mail—which actually behaves differently in full-screen mode—would seem to be Apple’s gold standard for a full-screen app, and you’ll have a hard time making use of that secondary display with it.
But what if you could full-screen Mail on your secondary display, while your primary display was still being used for other apps? There might be a utility to that. Or, to take a somewhat more common use case, what if you want to full-screen a video in QuickTime Player on your secondary display while working on your primary display? Give it a try under Lion, and you’ll end up with a main screen full of linen.
Be fruitful and multiply
Granted, there are challenges here. If you’re extending a desktop over two displays, Apple treats it all as the same space. But full-screen apps are also treated as their own spaces, which makes it tricky if you want to put an app in full-screen mode while still leaving other windows available in that space. Still, I’m convinced Apple could find a way to meld these approaches to allow the option of having a full-screen app available on one display while other windows or apps available on a secondary display.
The current previews of Mountain Lion don’t seem to make any improvement to the situation for those of us with multiple displays; the feature is basically unchanged. And Apple recently put up a support document, helpfully entitled “OS X Lion: Full-screen apps appear on the display containing the menu bar,” for which read: “It’s not a bug, it’s a feature!” Regardless, it’s a shame: The paltry support for multiple displays remains one of my few quibbles with the state of Lion. But thus far, Apple seems to have other fish to fry with its next update to the Mac operating system.
I don’t think, as many seem to, that Apple is iOS-ifying OS X, and that some day we’ll all be running giant, full-screen apps on our devices and loving it or else. The company’s smart enough to realize that it’s downright useful to be able to refer to one window while doing something in another—say, writing in a text file while looking at relevant details on a webpage. Or if you’re a graphic designer, a Web designer, an artist, a film editor, a programmer. The list could probably go on.
What it comes down to, I think, is that Apple sometimes gets overenthusiastic about an idea, without thinking through all of the repercussions, and such is the case with this process of bringing iOS and OS X into a more perfect union.
In fact, as long as the company is looking to unify elements of iOS and OS X, it could do worse than figuring out a way to bring the idea of multiple apps on the screen to its mobile operating system. That’d certainly be one way to make working on the iPad even more attractive.
[You can have senior associate editor Dan Moren’s second display when you pry it from his cold, dead hands. Well, maybe not dead.]