From the side you can see that the cathedral has a balanced distribution of mass. Other than e.g. the cathedral in Cologne, where the centre of mass is on the western side with its two characteristic towers, the centre of mass here is rather in the middle of the building. Contributing to that are the four rather small towers and the western building with the so-calles emperor's room.
This is the view from the steps of the Historical Museum. From here you can see the sheer size of the cathedral very well.