A couple days ago Helen Hou-Sandí live tweeted her first time trying out Gutenberg, the feature plugin for the next generation WordPress editor. One of her tweets stood out to me and started a thread: 36) I still wish there was a good way to preview featured images in different contexts. What will this look like in an archive vs. single?
So how can I understand how a featured image is going to look in all those contexts? How multiple changes look all together?
— Helen 侯-Sandí (@helenhousandi) August 2, 2017
tl;dr You can use the Customize Posts plugin to add and edit posts in the Customizer and preview your changes—to the title, excerpt, featured image, etc—on any area of your site where the post may appear. Here is a demo video that shows the plugin in action along with the Customize Snapshots and Customizer Browser History plugins in a child theme of Twenty Seventeen:
Framework for Previewing
The problem of post previewing is something I’m really interested in. Post previews in core don’t work for postmeta (like the featured image and page template) and you can’t preview changes on anything other than the singular template. Actually,