Your problem is that you are searching the post type of products. The information about each image is not associated with the product, this information is part of the post for the image which is an “attachment” post type. If you want to search images then you need to search attachments.
$args = array(
'post_type' => 'attachment',
'post_status' => 'inherit',
'post_mime_type' => 'image',
'order' => 'ASC',
'posts_per_page' => -1,
's' => $s
);