Featured blog image not showing on Twitter

I just set up and started posting to my blog, and I am noticing that for some reason, the “featured image” is not showing on Twitter. It works on Facebook and other platforms. Non-blog pages also seem to work just fine, but for whatever reason the blog featured image is not showing on Twitter. I installed the Yoast plugin (although am using the free version) and tried several other different social plugins as well but nothing works. The featured image is set correctly (since it appears on other social channels). I’m wondering why it’s not working on Twitter and if there’s something I need to fix or a special plugin I can download to make it work?

The page I need help with: [log in to see the link]