It's a new feature - I clicked on the blog link for the first time in a couple of months.
I have everything set up so that I do the print fulfillment, and in the past, I would have to contact the customer afterwards and settle payment. Now there an option where at checkout, they can pay either by credit card or directly through paypal.
What I was wondering is whether Zenfolio is charging an additional fee for the CC transaction, but it doesn't look like they are.