I have noticed an example of top-down processing recently while playing the new app pokemon go. The app has a feature that tells you there are pokemon nearby and if you have yet to caught a pokemon it is just a shadowed outline of the pokemon with no color or features. You can see an example in the photo below. Now to anyone without knowledge of pokemon it is just a nameless gray shape. However, with previous knowledge and through top-down processing I know that this gray shape is a Snorlax.  

This example of top-down processing is very simple and easy to understand. You need previous knowledge of something and the right context to guide the information collected into something with meaning. With no previous experiences with pokemon the gray figures in the game are just that gray figures. They have no connection to anything in your previous knowledge so top-down processing does not occur and they remain gray figures with no meaning.

On the same note the Pokemon show had a short segment before and after commercials called who’s that pokemon. Where they showed a gray figure of a pokemon before the commercial and showed the pokemon after commercial break. This was the same example of top-down processing in different context.