I think the encapsulation probably refers to the 'city in a building' aspect, i.e. residents have most needs satisfied within the building, and rarely need to l

I think the encapsulation probably refers to the 'city in a building' aspect, i.e. residents have most needs satisfied within the building, and rarely need to leave the building itself. cf. https://en.wikipedia.org/wiki/Arcology https://en.wikipedia.org/wiki/Arcology