apple can get away with minimal design on the packaging because EVERYONE on the planet already knows what the product is about without having to read the box. the box could be completely faceless and just have the word ipod and apple stamped on it on the underside where no one will see it and the product would still sell.
There was a time, not that long ago, when plain packaging like this was considered 'cheap, no frills, generic'.
It wasn't what you thought of when you thought of the word 'quality'.
Just told you what was inside.
It was often of lesser quality and price than even the basic store brand.
A plain white box with the word 'ipod' wouldn't be much different, except for the price.