Conversation during the 50th Front-End Study Hall (https://indieweb.org/Front_End_Study_Hall) this past Tuesday sparked a goofy idea, so I brought it to life with a quick in-browser mockup and a little @acornapp work.
@Meyerweb @acornapp "a torn page with a folded upper right corner showing a pink triangle, green circle and blue square; a missing image icon" would be good alt text
@Meyerweb I like the Zen challenge of providing alt text for a non-existent image, though. "Disappointment and a jarring reminder of how fragile the web really is"