Images not downloaded with Walllabagger, but imported from Pocket

I have Wallabag selfhostd on Docker, I have connected it to Pocket and after several time-out retries, I managed to import all my articles. They look fine, with all images.
Then I added Wallabagger to browser and set all the URL/ClientID/SecretID, etc.
It works, it grabs the article and adds it to Wallabag, but instead of showing the presentation image of the article, it shows a generic Wallabag icon.
I have deleted the article and imported it from Pocket: this time it had a presentation picture.
So Wallabagger seems to ignore images, but Wallabag is able to get them if coming from Import (Pocket).

No source file or test is named. Reproduce a save through Wallabagger and compare the resulting article and image-related data with an article imported from Pocket; trace the browser extension's article-creation request. The issue is done when directly saved articles retain their presentation image instead of the generic Wallabag icon.

Written by the indexing model from the issue text.