What are some common mistakes that can lead to the error message "Resource interpreted as Image but transferred with MIME type text/html"?

When you encounter the error message "Resource interpreted as Image but transferred with MIME type text/html," it means that the server is sending an incorrect MIME type for the requested resource. This issue can be fixed by ensuring that the server is configured to serve the correct MIME type for images, such as "image/jpeg" or "image/png."

<?php
// Set the correct MIME type for images
header('Content-Type: image/jpeg');

// Output the image data
readfile('image.jpg');
?>