THUMBNAILS GIVE A FAST OVERVIEW

Summary from the TLDR Design newsletter

Thumbnails let people choose by looking rather than reading, because a scene's gist registers in about a tenth of a second. They fail when neighbors look identical or a preview misrepresents the click, so the two rules are: differ from your neighbors, and resemble your destination. Fourteen guidelines follow, along with the risks AI brings when it selects, personalizes, or synthesizes previews.