The Guardian has published an interview with the designer of the original desktop icons for Apple and Microsoft, Susan Kare.
"Steve Jobs had an amazing ability to focus on and contribute to almost every aspect of the product," said Kare.
The aim of the project was to design computers non-engineers could use - computers for the rest of us. Graphics had to be understandable and were limited in size.
Discussing the icons used in today's operating systems, Kare said: "The current icon guidelines focus so much on illustrative style," adding that the focus is on simplicity, she says "the best icons function more like signage than illustrations."