Above is my friend's driveway, just up the road from where I live. I had to wait a few months for the snow to go away, but I remember thinking: "That's another Serpent Gateway!"
There's the Law of Parsimony at work here: it was easier to leave that big stone alone than move it (just like it was easier to take the photos without getting out of the car). I am going to make a guess that the other side was easier to take apart when it came time to widen the old "cart path" when Buford built his house and put in the driveway.
I wonder if he has some "before photos..."
Could be a suggestion of a snake eye, looking out toward the Old Indian Trail to Nonnewaug, just before it meets up with CT Rte. 6 that was the Old Connecticut Path.
And maybe, when seen just right, it's also somewhat Anthropomorphic too perhaps...