There’s probably a bunch of permissions errors, filesystems warnings for cross-filesystem mounts or links, etc. all going to stderr. Linux output streams are a bit odd, 1 is stdout and 2 is stderr. So the command is redirecting the “noise” to null and just printing the actual command output. That would be my assessment, but OP could probably give a more correct answer..!

2> means stderr.... Keeps the "can't access ...." Out of the display.

That's stderr, not stdout