I noticed in my matched and moved SK batch of files that I am seeing a lot of really large and small cover art images. I have SK set to ignore anything smaller than 400 and resize anything larger than 800. The large files are the same both in the tags as well as the saved file. I have Save Artwork to file system check. I have checked out a few of these on musicbrainz and they were the same images and sizes.
Also SK seemed to use any images it found, even ones smaller than the 400 i have set as my minimum. For example, in one folder alone I am seeing images as large as 2860x2778 and as small as 130x127.