It's kinda one of my hobbies to pick apart advertising/movies/political pictures for the errors. Graphical Arts types will routinely flip images creating objects that don't exist or will copy and paste stock photos that have no relation to the content subject.
I can understand that most of these projects don't allow the time and effort to get it right, but it's still fun to "find Waldo" in movie posters ads and other sorts of media.
The thing that disturbs me is when this kind of thing shows up in news or advocacy media as evidence of some point.