class.upload.php is a powerful and mature PHP class to manage uploaded files, and manipulate images in many ways. The script is available under a GPL license.
more info about the class
$handle->allowed = $handle->allowed = array('image/jpeg','image/gif','image/png');
file_src_name : Zapis_ki.zip
Your system detects the MIME type as application/x-zip:
MIME type detected as application/x-zip by UNIX file() command
But in your code, you allow only images: