From @Michael:
There is a bug in Lookup/Typeahead search, that the thumbnails of results are not updating when typing more characters and thus loading new results. Is that known?
It can be reproduced on the Codex documentation with the "Search Wikipedia articles" example: https://doc.wikimedia.org/codex/latest/components/demos/typeahead-search.html#search-wikipedia-articles
And I can partially reproduce it on production enwiki: The actual search-box seems to be fine, but where we use that for CommunityConfiguration, for selecting an image from commons, there it is broken too: https://en.wikipedia.org/wiki/Special:CommunityConfiguration/CommunityUpdates (edited)