As of today, 924 days have passed since the cowbell was first posted. As time passed, the standards were only set higher, so using such articles for a comparison doesn't mean too much.
Regarding the ideas, the Mood Lock seems interesting but describing the effect could potentially be problematic, seeing as unless someone had prior knowledge of how it works, understanding its effects would take a lot of time to figure out (and thus writing it up in a report could be difficult).
The Memorial Printer might work, on a smaller scale. Depending on how big the "photographs" are, that would take a lot of paper and ink (take a look at these statistics) I'm not entirely sure if something similar to it already exists, but I like the idea of the printer adding scribbled notes about the deceased that people may not have known, even when they were alive.
For the last idea, take out the "cleanest wall in the world" comment and you might have something workable… though it did occur to me to wonder, "why not just repaint the entire wall?" As Mackenzie said though, I'd recommend drafting it up to see how it goes.