Reading the newsfeed of the Danish Broadcasting Corporation was annoying me a bit, because the pictures they include are huuuge.
It would be nice if they were scaled down a bit - but I don't want tiny images scaled down as well...
Lo and behold, Lars has already solved this problem in
shr.el, the HTML-renderer used in Gnus (and eww): setting
shr-max-image-proportion to 0.5 on the topic of all my Atom/RSS-based groups → hey presto, problem solved.