Excerpts are meant to work as a simple teaser. They are usually text only. Because of this, you’ll not find a toolbar on top of the excerpt textarea when writing a post. However, if you do want to spice up your excerpt there are a few workarounds.

Probably the easiest way to get some formatting and images into your excerpt is to first write and style it in the body (post) area of your post. When done, click on this button:

This will show the HTML of your text. Copy the HTML and paste it into the excerpt textarea. Click on the <> button again to return the post area to the normal view. Don’t worry about the excerpt still showing the HTML. This is a workaround remember! This will be solved when you publish the post.