Steve Jobs said that Apple and its products were at the intersection of technology and the liberal arts, and the funny thing is that, probably without realizing it, dozens of times a day you click an icon on your Mac that explicitly exemplifies this.
Although I believe we don't know for certain, it's widely suspected that the Finder icon is influenced by the work of the cubist artist Picasso--possibly specifically by his 1934 painting Two Characters (detail above), though that might just be a delicious coincidence.
Since I have tacit permission from no less an authority than Jobs himself (since art history is one of the liberal arts), and only slightly because I never get a chance to use my art school education, allow me a tangent about cubism. The only reason I'm presuming to take up your time with this is because cubism is awesome, and simultaneously easy to be perplexed by and really easy to understand all at once--and I hope you get the same Damascene tingle as I did when it was finally properly explained to me.
Cubism, essentially, is about representing lots of different viewpoints of a subject all at once. That's it. So rather than taking a strict "photographic" approach to showing a face, for example, the cubists believe that you can get a truer, more complete representation of that person by showing their face from all sorts of different angles, perhaps showing different moods or different points in time too.
It's a similar line of argument as you could use to defend the unrealistic, flattened depictions of space that dominated art before the development of linear perspective in the early Renaissance. Before Brunelleschi in the 14th and 15th centuries, for example, a circular pond might be shown on a painting as a perfect circle rather than as a flattened ellipse as it would appear if you looked at it in the landscape or if you photographed it. But as the Bursar thinks in Terry's Pratchett's The Last Continent, modern perspective "is a lie. If I know a pond is round then why should I draw it oval? I will draw it round because round is true. Why should my brush lie to you just because my eye lies to me?" Just like with cubism, although these pre-Renaissance paintings look "unrealistic" to a present-day viewer, in some ways they're actually more fully realistic than photographic representations. It's a qualitatively different kind of realism.
So think about that the next time you click the Finder icon in your Dock! This cheery, smiling face, at once full-face and in profile (just look at the light blue half on the right, in case you've never seen it!), is a clever little visual trick that pays homage to the tenets of cubism.
Of course, this icon didn't always represent the Finder. Before OS X, it was represented in the application switcher at the top-right of the screen with an icon that looked like a compact classic Mac--and since there was even a time when Macs could only run one application at a time (until System 5's MultiFinder extension and its eventual integration in System 7), it originally didn't have an icon at all.
Picasso, though, was thought to have had an influence on the early Mac operating system even before the Finder icon was introduced, with the abstracted little series of colored squiggles that was used on packaging and which greeted you when you first booted the Mac.
Actually, though, it wasn't Picasso at all who was the inspiration for that playful design; it was Matisse. One of its co-creators, John Casado, told Cult of Mac, "The idea of the graphics being "Picasso style" was, as I remember, a journalist's description at the time of the launch. I think since no one ever ask me or Tom [Hughes] where the influence came from, it became fact." Which means I really should ask Susan Kare if it's true that her design for the little face that originally accompanied system alerts...
...was inspired by the design of the emblem Oskar Schlemmer created for the Bauhaus school of art and crafts in the early twenties (below). It's really tempting to draw the parallel between them because they look so similar, but it's possible that the flattened, highly simplified face in Kare's icon was just the inevitable result of the limitations of the rectilinearity of a pixel grid and of the space in which she had to work.
None of this, of course, was really what Jobs was particularly talking about when he positioned Apple at the intersection of technology and the liberal arts, but I nevertheless love uncovering these little hints and influences from the fine art and design worlds that have bled across to the Mac. It makes it feel like a richer, more rounded and more grounded place. And naturally, we are irresistibly reminded of the quote Jobs himself embraced, and which is often attributed to, among others, Pablo Picasso: "Good artists copy; great artists steal."