If you enter a feature description for your Jumbtron, this is where it will display. Background images are optional.
This page contains an example of an Internal Jumbotron.
An Internal Jumbotron is a bar that extends across the top of the page and contains a headline, and also provides the option for having a background image and description. (If you opt not to have a background image, it will render a gray background that looks just like the Feature Jumbotron.)
Internal Jumbotrons are made from General Content components.