Depending on the card that you use during checkout, you may see an extra security prompt put in place by the financial institution that issued your card to confirm that you are the authorized cardholder. This helps reduce the risk of fraud on your account. For more information on Verified by Visa, please visit http://www.visa.ca/en/personal/securewithvisa/vbv/index.jsp.
3DSecure would need to be verified when enrolling, and adding cards to VCO. These fields would be needed for a purchase as well, but are not necessarily part of the lightbox. This is included mostly before adding cards to the VCO account directly from the lightbox, rather than the actual purchase.