These files that don't get displayed on the Mac, do their names begin with a period ( . )?

These would be files that are normally hidden from view in the Finder. There are many, many hidden files on the Mac drives and they are hidden for a reason. They can easily be made visible, but is strongly advised when they are. Do not move, refile or delete any of these hidden files or folders. And the best advice is to make them invisible again when you have completed whatever task it is that requires them to be unhidden.

You can of these hidden files ON and OFF in a Finder window by pressing (⇧⌘.)