On developer.amazon.com there is an option to add multimedia images
and a place to insert your app icon
When I updated my app, I added new icons just like this. Now that my app rollout is complete, when I go to amazon.com to view the app listing, it looks like the old app icon.
How do I update the listing on amazon.com? Is there a separate place to do it? I can't find anything online.
Yes, the Images & Multimedia tab is the right place to update your app listing on amazon.com. Once you "save" the changes, be sure to click "submit app" to publish the changes. It may takes couple hours for it to propagate.
You may also want to clear your browser's cache in case it's caching the old images.