Created attachment 6360 Proposed patch Not all media has the media type information in the tag, so just picking up GST_TAG_IMAGE_TYPE_FRONT_COVER means no thumbnails are generated for those.
Created attachment 7129 PATCH audio cover thumbnails Just want to bump this patch (and the one in https://bugzilla.xfce.org/show_bug.cgi?id=12030) to see if we can get this included in the next version of tumbler. These two patches together (combined in the attached patch and patchable against current git) will easily give us album cover thumbnails for audio files.
*** Bug 12030 has been marked as a duplicate of this bug. ***
ToZ referenced this bugreport in commit 4a5191bb18d7d3ee3c39ac0a95da2f43e1e14b2d Add more media types for audio cover thumbnails (Bug #12041) https://git.xfce.org/xfce/tumbler/commit?id=4a5191bb18d7d3ee3c39ac0a95da2f43e1e14b2d