Thank you for the credentials, your assessment on your "secure note" is right. Your site is still requesting the images from your development environment (/wp/ which are not existing anymore, right?).
Please try clearing all your caching plugins and caching feature.
If clearing cache did not work, then that means your migration process did not go quietly successful (how did you migrate the site? What plugin did you use?). If you can't redo the migration process anymore, then I'm afraid that you need to re-set those background-images manually.
Or you can download your page template (.csl), then do a find and replace on the downloaded file. And upload it back after.
Hope it helps,