readlink reads the contents of a symlink, and
readlink -f follows symlinks to symlinks to symlinks, etc., until it finds something that isn't a symlink.
This isn't necessary for scp though: scp always follows symlinks (it always copies file content, ignoring metadata except that
-p preserves file times and modes when possible).
If you find yourself disappointed by what metadata scp can and can't preserve, I suggest using rsync. With no option, rsync copies file contents ignoring metadata. The commonly used option
-a preserves all garden-variety metadata (times, symbolic links, permissions and ownership), and there are options to preserve exotic metadata like ACLs and hard links.