Is_dir across drive from C: to D

C:/xampp/htdocs/Cirectory/test.php
D:img/Directory/

I have directoris and a file named “test.php” like the above.

I have the code below in test.php

$myDirectory = '../Cirectory' ;

if ( is_dir($myDirectory) ) {
echo 'TRUE' ;
} else {
echo 'FALSE' ;
}

it says ‘TRUE’ ;

I like to check is_dir with “D:img/Directory/”.
I change the value of the variable $myDirectory like the below.

$myDirectory = "../../../../D:/img/Directory" ;

However, it says “FALSE”.

How to make it says “TRUE”?

VirtualHost is designated like the below.

 <VirtualHost *:80>
 DocumentRoot "D:/img"
 ServerName img.myDomain.com
 <Directory "D:/img">
 Require all granted
 </Directory>
 </VirtuqlHost>
$myDirectory = "D:/img/Directory" ;

Thank you very much