In my alternative fantasy Boston, that section over the highway portal is structured more like a real square. You know, with a big fat island in the middle, may be with some trees and a fountain, and some thoughtfully defined negative space inset in the new positive volume created by the new landscrapers ... (and including the nice little corner plaza defined by the lovejoy passage and bev st extension). Capped off by a prominent entrance to the Garden / NS holding down the adjacent corner of the new building, and with the vertical volume (and spire) oriented above that corner towards the square (rather than to simply being orthagonal to causeway st.)
Right now its a nice little pocket park, and the Tavern on the Square sidewalk eating is nice. Huge upgrade, obviously.
But it could have been a coherent defined/design space and its not.