Restoring from Time Machine and Disk Space Issues

I want to restore my Documents and Pictures folders from Time Machine, but I keep getting this error message:

The item "Documents" can't be copied because there isn't enough free space.

I thought when restoring from Time Machine, it moved all your folders, etc., back to where they were at that point in time. This message seems to imply it is trying to copy that folder structure to the current, which would mean duplicate files, which wold explain a lack of disk space.

But I am still new to TM and could use some help here.