When you are exporting an attachment value from the API the JSON object has multiple properties: url, width, height, etc. We have made it possible to distill the JSON down on our platform, https://www.csvgetter.com.
This means, if you'd like just want image URLs in an Airtable CSV export, you can do it quite easily now. Check out this brief video demo of how it works:
https://youtu.be/4IvIj0ir-BY