When I used the https://web.whatsapp.com/send?text={url_encoded} as suggested above i got something like this (https://tajrebatee.com/page.php?i=item&id=266) which shares the link but not the thumbnail or preview (this was working before I make the WhatsApp web update they suggested).. The part (&media={img_url_encoded}&description={title_encoded}) I copied from the share equivalent part of sharing in Pinterest.