That's exactly what that means. The torso is split in two, from the side. Matrix and abs in the front half, head and arms fold out of the back half. It looks like the shoulders and biceps will fill in the back for truck mode, so that the smoke stacks peek out. Pretty much just like their Ratchet and Ironhide. They're both a bit open in the back. In all fairness, there does appear to be a back portion in the "LOOK AT MA AXE" pic that doesn't seem to be present in the "LIGHTING DARK HOURS" pic. The dangers of sharing prototype pics..