During the preparation of a general audience talk on why mathematicians use dimensions higher than three (or four) even for concrete applications, I came up with the following enjoyable observation : Taking the negative of a picture is a central reflexion of the hypercube. I'm pretty sure many people already observed this, so my question is :
Are you aware of other similar transformations for "everyday life high dimensional objects" which have a nice geometric interpretation?
To provide more details, consider a picture of $240\times 240$ pixels, where each pixel has a grey level ranging from $0$ to $255$. Each grey level can be written as a $8$ digit number in base $2$ (and now your computer understands what grey level means). With this identification, this picture is a vertex of the $$ 240\times240\times8=460800\mbox{-dimensional hypercube: }\quad [0,1]^{ 460800}.$$ Now, the negative of a picture is the picture you obtain by reversing the grey scale, meaning mapping a grey level $\alpha$ to $255-\alpha$ for every pixels. In binary this means you switch every zero to one and vice versa. Thus the negative picture, seen as a vertex of the hypercube, is the central reflexion of your initial picture with respect to the center of the hypercube.
I would like to see if one can find other examples of nice geometric interpretations for (colored or not) image transformations, sound effects (i.e. Fourier series of reasonable functions), etc.