The titles on the Shine theme are underlined and look like this:
These title underlines are displayed by default, but you can remove them if you wish.
To remove the underline, open up the Colours and Design Featured tab in the customiser.
Scroll to the bottom of this tab and here you will see the Title Underline section and the option to show the title underline. To hide the underline, simply untick the box next to this option.