What's the deal with this trend of novels announcing in the title that they are, indeed, novels? Currently on Amazon bestsellers: "A Tangled Mercy: A Novel", "The House by the River: A Novel", "Origin; A Novel", "Everything We Left Behind: A Novel", "Beneath a Scarlet Sky: A Novel." I could go on, but I suspect you get the gist. What is the point of this? We don't feel the need to say "Pulp Fiction: A Movie" or "The Golden Girls: A Sitcom" or "Fruity Pebbles: A Cereal." Why are we hanging a lantern on novels being novels? It reeks of pretension. I hate it. Make it stop.
It's not new at all. And you're comparing apples to oranges here. If you'd said "To Kill a Mockingbird: a book" then it would be as ridiculous as "Fruity Pebbles: A Cereal"
But books are objects, and unless you know one of them is a novel you can be forgiven for not knowing that Star Wars isn't non-fiction about Reagan's missile defense system.
Uncle Tom's Cabin isn't about real estate.
Huckleberry Finn isn't about muffins
The Breach isn't about babies.
The Electric Church isn't about religion (or Jimi Hendrix)
Putting "a novel" on the cover helps the folks unpacking books at the bookstore to know what it is, without checking a packing slip.
A lot of agents fall prey to this when talking to writers at conferences. They fling terms and "rules" around like their audience should know what they are talking about. Well, none of us were born knowing Fruity Pebbles is a cereal; or a query letter is how to contact an agent; or, The Breach is a terrific novel.