Yes, some of the larger houses would have originally been on estate-sized properties that were later subdivided as townhouses and shops. This was the more desirable end of town and it was one of the first areas where nicer homes were built.
Here's another old postcard showing a rare view of Barrington Street and George Street circa 1920. Unfortunately, the foreground office building on the right was torn down in 1990 or so for an office development that was never built. On the left in the foreground is the old TD bank building, which wasn't very impressive, but that is the site of the modern TD office tower. Behind that building are the five storey Royal Bank and Bank of Montreal office blocks that were built around 1870. Unfortunately they also became bank towers.
The two cupolas in the background are for the old post office and customs house. The post office is still there, but its cupola has been removed. The customs house was torn down in the 1950s. This is one of the worst streets in terms of losses of significant heritage buildings in Halifax. Even those little buildings down near the end of the photo are long gone. They might not have been anything special but there isn't really anything there today.
(hosted by me)