The following code will behave differently on binary file field type and image field type.

$newField->validatorConfiguration = array(
    'FileSizeValidator' => array(
       'maxFileSize' => 2 * 1024 * 1024
    )
);

on image = 2 MB = 2097152 B
on binary file = 2097152 MB

And on image if we set a value less than 1MB (1024 * 1024) the value set will be 0.