Almost all stacking chairs will lose a reason for their existence if they are stacked; they will become something that we want to put away. In contrast, this product is usually a shelf, and will become a chair when you need it.
What has not been done by using rapid prototyping technique? My answer is making sounds. It must be difficult to make music but it could be possible to make noise. When you put a seashell on your ear, you can hear something strange noise. It is noise but it makes us feel good. This product is a wearable instrument for listening the noise like seashell makes.