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It's time to talk about my writerdeck
(veronicaexplains.net)
This is a most excellent place for technology news and articles.
Apparently there are escape sequences for it; see my response to the parent post.
Even if there weren't, if a given terminal supported either the older Sixel or the newer KiTTY graphics protocol, it can outright display arbitrary images.
Mainline tmux doesn't support either protocol, though there's a fork that does do Sixel. They're using tmux, so I assume that that's not the route used.