On Mon, Jan 1, 2018 at 10:35 AM, Bartosz Dziewoński matma.rex@gmail.com wrote:
The first of these pages has a "thumbnail" defined, the second doesn't. Unfortunately I don't know what generates this data, but perhaps someone else can help.
In that instance, I believe it's not using the image because of the aspect-ratio (very short-and-wide).
Whether an image is available to the hover-previews is determined by https://www.mediawiki.org/wiki/Extension:PageImages#Image_choice (then Extension:Popups - the "page previews/hovercards" extension - just uses that.). For example https://fr.wikipedia.org/w/index.php?title=Louve_(outil)&action=info (image) https://fr.wikipedia.org/w/index.php?title=Pince_universelle&action=info (no image)
Moreover, I have a feature request : it would be great if the edit-preview would also display the hover-preview so that you can validate your modifications also with respect to the hover-preview of the article.
Good idea. Filed as https://phabricator.wikimedia.org/T183870
Happy new year :)