The *building* here, with the municipal address of 751 - 3rd Street SW, is still the Calgary Eaton Centre. The overarching "Core" mall includes this building, but this building does not solely constitute the mall. It is but one part of it. Make sense?

In point of fact there is already a node nearby denoting the mall, see https://www.openstreetmap.org/node/4267852312/history