Logic Behind the Orientation of Bay/Barrel Fronts?

After doing some of the research suggested on this website, my husband and I were able to locate the floorplans for our townhome built in 1907. We’ve got a bunch of questions that I’ll be posting about if I can’t find answers on the forums, but the first question I have is regarding the orientation of the “barrel” or “bay” on the front of our house. (The realtor called it a barrel-front, but it’s three sided so I have no idea if that’s the proper term.)

Our house is attached on one side to an identical house next door. (So the “row” is only two houses.) The first surprise when we got the blueprints was that the house appeared to be a mirror image on the floorplans. We then realized that the blueprints listed were for two buildings on our street and the street behind us — so the builder built all four at once — but the ones on the street behind us are inverted. So, basically, the “barrels” are oriented towards the east for both homes, even though they’re oriented in the opposite direction, which means they’re mirror images of each other.

Anyone have any idea wh y this might be? Is there a reason the “barrels” are supposed to be oriented towards the east? If not, any thoughts on why a builder would invert plans for otherwise identical houses? [Capture](//muut.com/u/brownstoner/s1/:brownstoner:cKWp:capture.jpg.jpg)