For XenForo 2.2.x with article forums without a attachment set in the thread. You can define a default cover image for the preview style, not for thread view, so the are no blankets anymore in the preview grid style.
Installation
Auto-installation
Go to ACP->Add-Ons and upload the ZIP file...
JoyFreak submitted a new resource:
[JoyFreak] Article Cover Extended - Adds article cover image to tags/search results.
Read more about this resource...