Mike wrote to let me know that the Mac OS Ken album art was spotted on GigaOm's review of the Podcasts 1.2 update from Apple. Their takeaway:
With the Podcasts 1.2 update released Thursday, Apple’s own app is now on par with other iOS podcasting apps. One area in which it really excels now is automatic downloads of new episodes.
Plenty more in the review. I'm just going to keep looking at the pictures, though.
Thanks, Mike, for the heads up!