Why do they ask for a PHOTOCOPY of IMM1344B, not original?

[universalmoe]

In the Document Checklist, under Forms for Sponsor, it asks for
2. Photocopy of completed Sponsorship Agreement (IMM 1344B), signed by you, your co-signer and the person you want to sponsor

Do we provide a photocopy or the original; not sure why they wouldn't want the original?

Thanks...

 

[Boncuk]

Because the original should be with you as it is a contract between you and your spouse
They just want a copy that shows it was signed by both of you. Technically you should have one and your spouse should have one in your possession.