Due to the fact that the hood scoop is closed off, it prevents air from entering. Obviously. Due to that fact, and similar to a truck bed, a vortex (or circulating air pocket) is stuck there, and the rest of the air flows over.
Things to keep in mind about a using the hood scoop like in the first post, is that the engine will suck the air in. A s/c engine will do more so. So if your design still uses the factory opening on the fender well, as well as what is in the photo above, it will get fresh air from two sources.
One thing about the scoop though, is that it won't be getting the air that has been heat saturaded from the baking road surface.