Podcast feed image not showing up

The Store can be a bit sticky about podcast images sometimes. Once a new image is uploaded it can take quite some days before it appears; your image is correctly referenced in the feed and since its filename includes the size you evidently changed that from the previous image (which is important), so it's juste a question of waiting until the Store condescends to show it.

There is no problem with GoDaddy (the new requirements apply only to the media files, only on an iOS Device, and GoDaddy is compliant with this anyway).

I'm afraid the Store is just being very sticky about this - it's not that unusual - and you can only wait until it finally decides to update.

You could try emailing Support at podcasts 'at' apple.com but frankly I doubt that you will get much of a helpful answer.