Well to be fair, the image in question shows the people in what is presumably a cold environment. Assuming that that is correct, then it is possible that they are wearing cloaks, not capes, for warmth (perhaps further reinforced by the addition of what appears to be some kind of animal fur). As for the walking vehicle thing, it is possible that it was built to walk for better performance in rugged environments that would otherwise be hard to reach for ground vehicles (think AT-ATs from Star Wars). All that being said, this is concept art and we don't even know if the subject in question is even human judging by the 4 glowing eyepiece things on the helmet.