Imagine the fresh smell of cuban food as you watch Chef or the sweet smell of raisinets melting in popcorn as you watch Whiplash. This would add a whole new sense to the theater experience. "Smell-O-Vision" could open new doors for audiences who have trouble staying awake in films. It would be hard to sleep through the smell of maple syrup that would often arise during a screening of Elf. However, there are certain times when "Smell-O-Vision" might take us too deep into the film.
While "Smell-O-Vision" would work for food-based films, it might not fit in with other genres so well. For example, I would probably have to walk out of a "Smell-O-Vision" screening of Swiss Army Man. As much as I love that film, I would prefer to watch it without the constant smell of Daniel Radcliffe passing gas. Other problems might occur during a screening of Zootopia or Babe. Animals might be fun to watch on screen, but they probably wouldn't be quite as fun to watch with their natural smell.
To sum up, "Smell-O-Vision" could open new roads for cinema. But there might be roads that are better less traveled in this case!