Teaser Headline
Using the Teaser Settings, you can add a Teaser Headline for your post and this headline will be displayed on the Homepage, Section and Tag pages before the user actually clicks on the article.
Teaser Image
Same as the Teaser Headline, if you choose to have a Teaser Image, it will be displayed instead of the Main Image before the user clicks the article. When adding a Teaser Image, you will be able to edit it the same way with the Edit Media Tool.