Question:

What is stored in the Attachment object for Approved Email in CRM?

Answer:

Attachments for Approved Document stores the Veeva Preview rendition. This is the HTML rendition created by Veeva Vault that contains images stored in base-64 formats. It is used by mobile devices when previewing the email. 

These are created whenever the Approved Documents records are created in CRM. 

All approved doc attachments have AppEmail__ prefixed in the names.

Thank you