I don't remember much of the dream, but we went through a home and it had several Roombas. My companions didn't know Roombas and I explained it to them. Then we encountered one in black and silver that was about 60cm in diameter and about 1m high, but built like a wedding cake with sections getting smaller towards the top and the top was more like a recrangular head sensor array. It had a large spinning ring wiper on the bottom, surrounding its wheels. Then I had to explain how to maintain it and opened several compartments and everyone was like "woah". It was a modular design; easily replacable parts like all roombas are IRL, just huge.