aldenp: That really depends, if you're directory you are pinning is structured like:
```
/parentdir
-> file1
    ->file2
    ->file3
-> file4
    -> file5
    -> file6
```

If you have previously added `file2` and `file5`, and you are pinning the CID for `parentdir` then you wouldn't download `file2` nor would you download `file5` but you would download the `file6` and `file3`