+1 I thought it was quite impressive until reading that comment from someone who works in the design field!
*not all design people, just a certain flavor
2. "concept art" for a tiling wm makes no sense, because as you point out, it is first and foremost something that is work focused. This is why you build functional prototypes.
Concept art for a tiling window manager certainly does make sense. Especially if you want to define the appearance of one.