jefferyto
commented
6 years ago I'm planning on making a few more image-related changes (for custom header images and post covers with post titles overlaid on top), but it looks like if I submit them as separate PRs they make conflict with each other.
I'll close this one now, then later open a new PR with all the changes in one branch.
This works with the built-in responsive image functionality added in WordPress 4.4, to allow browsers to download smaller versions of content images and full-width featured images when possible.
These changes are modelled after similar code in the Twenty Sixteen and Twenty Seventeen themes. (Current code for these themes are slightly different than their GitHub versions, but its much easier to link to the GitHub versions :laughing:)