I don’t know if this particular display is magnetic particles or not, but epaper is not synonymous with eink. Something can be called epaper and still be lcd based. So I feel the video is misleading by declaring epaper is particle based.
Some 15 to 20 years ago there were a lot of other companies trying to create reflective (= e-paper) screen technology based on principles other than electrophoresis, some with native color or fast pixel response times, but they all closed shop.
The only other major type of e-paper that is still used is simple reflective greyscale LCDs. These are not bi-stable but achieve fast pixel response times. The main disadvantage is that they have significantly worse reflectivity, resulting in rather greyish whites.
Is one a subset of the other? If so which is the superset?
E-paper is an informal category that anyone can use for any display type.
The display in this video/article is also electrophoretic, but not all displays called e-paper are and it’s aggravating. An example: https://kentdisplays.com/products/color-epaper-displays/
"E-paper" means very little. It may mean "static" (and yet not necessarily "bistable", not even necessarily "efficient"), it may mean "reflective"... It is a marketing term.
So no, there is no real "agreed understanding" in it.
I would not be sure about that "everyone" - yes, clearly it should mean "reflective" (or similar, i.e. "improving visual conditions"), but it also may mean bistable or approaching that ("efficient"). (Paper has many different advantages.) Technologies to approach "better reading" features vary - in the tricks and in the gains. The term "electronic paper" is so slippery that in fact online news brodcasters can call their web distributed content (online news-/non/-papers and magazines) "epapers". All considered, avoidable term, unless we are clear about the point in the specific context we mention it.
> not just a marketing term
I meant, "so easily employable as a simplification for the customers".