Unfortunately my Clara doesn't follow the USB standard. The USB standard says that the narrow part of the connector is supposed to be the TOP. Cables are labeled with the USB logo on the narrow side and you're supposed to be able to orient the cable using the side with the logo, but Kobo decided to use the wrong connector (they make top mount and bottom mount connectors to allow you to have the correct orientation), meaning that the cable must be turned backwards -- annoying.
EDIT: The cable that came with the device has the USB logo on the A side (the side that plugs into the computer), and is properly labeled and oriented, but the B (device) side is unlabeled too.