Visual cues one can make in their notes and user interfaces that help to focus or center on these can be useful reminders for what appears in particular notes, especially if visual search is a possibility.

Is this the reason that Gyuri Lajos very frequently cuts and pastes images into his Hypothes.is notes?

Which note taking applications leverage this sort of visual mnemonic device? Evernote did certainly, but other text heavy tools like Obsidian, Logseq, and Roam Research don't. Most feed readers do this well leveraging either featured photos, photos in posts, or photos in OGP.