It looks like it functions on electricity and the noice is coming from a generator that is required to provide enough electricity to run the actuators and computer. The generator is a bit loud, but this is a prototype, and if it is to be autonomous, it needs to have its own electricity source.
I see that it work well as a pack mule, how well would it do on a rigorous hiking trial like the grand canyon. It needs to have some sense of it surroundings and how to avoid them. One false step there and it is not going to recover.
Maybe that is asking too much of a robot, but I am sure it will be addressed in future prototypes.