You can add a custom title and subtitle to your post if you want to have a different title for the preview, and a different one on the post page itself.
- While editing a draft, click the ... icon.
- From the drop-menu, click Customize title/subtitle.
- Choose an option below and save.
When previews of your post are shown on Medium and around the web, the title and subtitle will be automatically pulled from the first few lines of your post.
Custom allows you to specifically define the title, sub-title and meta-description which will appear in previews.