I was reading Jane Austin Northanger Abbey 1817. She talks to the reader.
I read P. G. Wodehouse 1923. He talks to the reader.
I am reading A Dumas 1844. He talks to the reader.
It seems to me that it was a common way to engage with the audience back in the early days. I have read many old books that use the technique and I think I like it.
e.g. Now dear reader if I were to describe the fellow on the bus in such glowing terms that you might think him the salt of the earth, then you would be wrong.
In Literary Licence, my recently published books I give three words to the reader.
But the question is: Is it acceptable in today's modern world. Can we as readers be engaged by the author or do we just have to be entertained.
Plenty of movies have asides where the actor will give a look or a wink to the camera/audience. Why not in a book. After all, if you are writing it, who better to tell the reader about the character, place, time, emotion.