References: Cubebot, Wall•e
Wall•e is a box that expands to a robot. I don’t think I’d design anything as advanced as a biped, but it would be interesting to see what you could do with space that could be expanded. An umbrella, antenna, parachute, could all be in a small area and expanded out. What about a passive heatsink design that was a solid block but expanded or fanned out for cooling. Shipping of products would be different if all the empty space was taken out, but it could expand. Foam mattresses are recent proof of this.