External Design: each Instagram to WP post, with Featured Image, in specified WP category
Specify a Category defined in your WordPress blog. Then, each future Instagram post also appears as a post in your blog, in the Category you specified. KEY: the Instagram image will be set as the new WP post's Featured Image. Install WP plugin like "QQWorld Auto Save Images" to save the remote image to Media Library so it can be treated like a Featured Image in supporting themes. The Instagram caption will serve both as the post's body and as its title/headline (which you can truncate via CSS).