Social media sharing problem

This plugin seems very easy to understand and is fairly intuitive. But I cannot figure out social media sharing. When I attempt to share a photo to social media, it shares a link and looks like there should be a photo there, but it doesn’t actually show the image. I’ve tried it with FB multiple times, and when I tried it with Pinterest, it said there were no images to share. The sharing feature is the main reason I tried the plugin–that’s all I really need for what I am doing with the gallery I am making and it wasn’t possible with Jetpack and other plugins didn’t have it or it would cost a lot of money.