Image download works in Xampp but not in Hosting server

I'm trying to download an image JPG using PHP, I have successfully made it work in Xampp via localhost but when I try to do the same in my hosting it doesn't work (I have a Jetthost hosting with basically the same configuration of the Xampp server), here is the code:

The download button:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Button download</title>
</head>
    <body>
        <button><a href="download.php">BUTTON</a></button>
    </body>
</html>

The image downloading:

<?php

    //Read the filename
    $filename = 'image/balloons.jpg';

    //Define header information
    header('Content-Description: File Transfer');
    header('Content-Type: application/octet-stream');
    header("Cache-Control: no-cache, must-revalidate");
    header("Expires: 0");
    header('Content-Disposition: attachment; filename="'.basename($filename).'"');
    header('Content-Length: ' . filesize($filename));
    header('Pragma: public');

    //Clear system output buffer
    flush();

    //Read the size of the file
    readfile($filename);

    //Terminate from the script
    die();

?>

Here is how the files in the code editor are structured:

So, when I execute all that in the Xampp and when the image is downloaded it is alright:

But with all the same code in the hosting when I download and open the image it says this:

What is wrong???

Solution

I tried your code on my local laptop and server side as well, it works fine. I think while uploading to the server you may have forgotten to upload the image or there might be some spelling mistake in your image name.