Any pre-show that doesn't require you to watch it (like you can just pass by it as it goes on) I consider queue entertainment. While interesting to see the first time, if I get to skip past these things, I'm happy to do so. Indy's interactive queue, Space Mountain window views, Seven Dwarf Mine Train games are examples of these.
A pre-show that requires a room that you wait to go into, I'd say is the beginning of the ride/experience. These are things I would miss if someone snuck me through a door to the ride proper. Mansion, Tower, and Mystic Manor all have these types of required pre-shows.