That question intrigued me so much, I went and googled the manual. Reviews of the card on newegg were pretty bad. It's only PCI, not PCIe, so your throughput will be low.
Here's a great tidbit from the manual re: status lights:
Pin 2 represents SATA Port 1
Pin 1 represents SATA Port 2
Anyway, looks like this answers the "how" question:
"Many server-level chassis include hard-disk hot-swap bays. For these system
chassis, cables are attached to the chassis backplane, rather than directly to
each individual hard disk."