The event 'mw-mf-section-rendered' is triggered after a section has rendered
$( window ).on('mw-mf-section-rendered', function( ev, container) {
$( container ).find( ... ).hidpi();
} );
should fix this?
Not sure how to use hidpi though - can you point me at the code or look into this yourself?

The hidpi code is in core:
https://gerrit.wikimedia.org/r/gitweb?p=mediawiki/core.git;a=blob;f=resources/jquery/jquery.hidpi.js;h=70bfc4ea3c664570102bd697140912fedfd98373;hb=HEAD

$(foo).hidpi applies the 'srcset' stuff to any <img> elements found within the given selection, so assuming container is the container for the newly shown section this should work:

$( window ).on('mw-mf-section-rendered', function( ev, container) {

$( container ).hidpi();

} );

It should be idempotent if run over the same DOM subtree twice, so it should be safe to run it multiple times if need be.

https://gerrit.wikimedia.org/r/40326

• Bug 41287 has been marked as a duplicate of this bug. ***