A speedometer versus a digital speed read-out
It is tempting to see a speedometer as something that merely measures the speed of one's car. In that case, why not just replace it with a digital readout? I believe some cars have, but I think that is a mistake: The speedometer is not only giving a measure of your car's speed, it is a simple model of the car's movement, abstracting out a single aspect of it and showing a visual analogue of that aspect. The driver gains a feel for his speed while watching his speedometer climb that he simply does not get from watching a number change.