Thumbnails of image attachments are not consistent with other file types on deleted pages

Steps to reproduce

1. Create a page
2. Add some attachments to this page: some images (.png or .jpg) and some other file types, like a .txt and/or .pdf (for better observability)
3. Delete the page
4. Go to 'Page Index' > 'Deleted Pages' tab
5. Click on the deleted page
6. Click on 'Attachments' tab
7. Observe the thumbnail of the attachments

Expected results

All files thumbnails are consistent (a representative icon for each file type).

Actual results

The image attachments have a large thumbnail, taken from their filename (see attached screenshot), which doesn't happen with the other file types (tested with .txt, .pfd and .odt).

The issue doesn't reproduce on XWiki 18.4.7, where the attachments on deleted page were not displayed at all.