When user add the attachment at the time purchase order confirmation then the attachment should be appear on purchase order invoice/pending vendor invoice form as well.
Usually When we add the attachment at the time PO confirmation level then it is not appearing in the invoice form.

Following steps to navigate: The attachments in Purchase Order should be reflected in Invoice

1. Create a Purchase Order
2. Enter Lines and confirm the PO
3. Add attachments to the Purchase Order Form
4. Post Product Receipt for the PO
5. Click on the Invoice
6. Validate that the attachments from PO reflected on the Pending Invoice Form

Please encourage this new idea with your voting's, it will be helpful to have as per business requirements.

Thank you all in advance :).