Could you please provide me with a URL to your website, either here or via PM (click the “Private Message” text underneath my avatar) so that I may analyze it? It is a lot easier for us to diagnose issues when we have a live site to examine.
I can see everything is working fine. Problem is that the image is really small (219px x 219px), so there is not much to resize. Please use images at least 640px so after click an image will double in size.