Anybody know why?

Because its drawn that way?

sub to_string {
    my $self = shift;

    die 'DO NOT USE';

    if (   $self->version eq 'draft-hixie-75'
        || $self->version eq 'draft-ietf-hybi-00')
    {
        return "\x00" . Encode::decode('UTF-8', $self->{buffer}) . "\x
+ff";
    }
}
[download]

The method isn't documented, so pretend that it doesn't exist :)