“Perhaps Today you Gave a Nod- to Sweeney Todd”

In The Ballad of Sweeney Todd finale there are the lyrics “Perhaps today you gave a nod to Sweeney Todd” and the famous “isn’t that Sweeney there beside you?” With the “There! There! There!” as the cast points into the audience.

The most common interpretations I’ve heard is the straight forward idea that it is to scare the audience, almost as if a threat. But, I have also heard many other ideas and, personally, was looking at it as if it was the theme that anyone could be a “Sweeney Todd”.

I am posting to hear other people’s ideas and interpretations but also was wondering what is more likely to be the actual reason for the lyrics? If anyone who’s more educated on Sondheim or has heard him speak upon these lyrics himself, please let me know!