Where the Wikidata item corresponding to a Wikipedia article has an image and the article has no image, then the image should usually be displayed in the article.
On Wikispecies, this is done with https://species.wikimedia.org/wiki/Template:Image which can be used even when Wikidata has no image, in which case it displays nothing, but if an image is later added to Wikidata, then it is displayed in the article. Some infoboxes can also do this.