Photographing the fender liners is.... difficult. Search Google Images for 74551-SNA-A00 or 74591-SNA-A00 to get an idea. Installation is amazingly easy - just drill two holes in the fender area (there are dimples to show you where), insert screws, and pop in a clip. Took me five minutes in the dark holding a flashlight.
My car is black, so seeing the grill is quite difficult. I browsed for a photo of a lighter color sedan and found this.
It may be difficult to see but the honeycomb-textured plastic on either side of the main grill is solid save for maybe 1/5th closest to the center grill. In other words, no air is getting through. The upper grill (the portion with the shiny plastic and the H badge) does allow air through.