Right now, the search results overlay shows an image thumbnail for each result page. This makes sense for Wikipedia, but doesn't make sense for most of the other projects. For example, Wikiquote rarely uses images, so the search results always show a column of placeholders instead. Even on Commons you'll just see a column of placeholders since our thumbnail code doesn't consider images in galleries.
This functionality should controlled by a feature flag and turned off for all non-Wikipedia projects.