It should be used for billboard advertising. You don't even need that many PPI pixels per square inch because of how high above it is, and it would save ginormous bucks on printing canvases and technicians changing the ad. Not to mention, timed advertising.
When i read this comment i had to go look at the product because i was expecting 10-20k. Looks very reasonable to me. The most expensive is only $2500? and the cheapest only $600? Seems super inline with what I would expect to pay for art.
Also, with e.g. an oil painting on canvas, the cost of producing that is the time of the artist to paint it by hand. I don't think 10-20K is anywhere reasonable for e.g. a mass-produced inkjet-printed thing. Likewise 10-20K for a PNG file would be even more insane.
https://www.waveshare.com/product/13.3inch-e-paper-hat-plus-...
I just went through the process and made this for myself: https://www.printables.com/model/1189455-waveshare-133e-6-co...
The total price was around $420. This includes shipping, taxes (to Belgium), a pi zero w2, a sd card, and printing a case.
Are you happy with the quality?
Compared to the previous gen e-ink (7-color ACeP), the contrast and the colors are so much better. I also have a bunch of 3-color (black/white/red) panels - video and more pictures on https://frameos.net/ ) - and the contrast is similar, but the colors are obviously limited.
So yeah, I'm definitely happy.
Still, there's a lot of details to consider and trade-ofs to make wrt/ content, and Spectra refresh is also dead-slow.
Perhaps to their credit, E-Ink isn't even trying to hide the refresh in their marketing material: https://www.youtube.com/watch?v=Hr_EQaqTK0M (second half has a lot of examples of poster-sized Spectra 6 and Spectra 3100 panels).