It’s why you fall in love with Apple devices.
People generally question why an Apple fan is so fanatical about the company that manufactures their favorite device. There is a simple reason for that- other manufacturers make devices that people like whereas Apple makes devices that you fall in love with. The philosophy of Steve Jobs to perfect even the smallest bit of every device that might never even see the light of the day is what makes you fall in love with your iPhone or Mac. Here is a video demonstrating one such thing- a feature of iOS6 that was never mentioned in presentations.
The changing reflection, shade and shine of the volume button at different angles is completely useless from a functionality point of view but look at it from a UI point of view and you know you fell in love with Apple devices for a good reason. Their attention to detail is stunning.