<p>The Others: Click here to remove rwx for other (chmod -R o-rwx) from all files and directories. This cannot be undone!
The Group: Take it to the next level? Click here to remove rwx for group (chmod -R g-rwx) from all files and directories. This cannot be undone!</p>
These options remove all access to your files for everyone and optionally the group. Since PHP runs as the file owner on Cloud Sites, this allows the install to still function.
These permissions are more restrictive than those prescribed in the link you reference, which allow others and members of the same group to see your files.
Hope that helps.