The dashboard designer's Display tab is where you enter a title for the dashboard as a whole (the container title). Report component titles come from their respective Container Titles. If you see a report without a title and you want one, simply hop over to the report designer and edit the report and add a report Container Title. You might need to refresh the dashboard designer after you update the report title in the report designer.
See also Configuring Filters and Time Series Settings for Report Components, which is tab-independent as it is configured on each report component in the Preview Pane. You can move to any of the other tabs by clicking Content, Scope, Team. See also Using the Dashboard Designer (Beta) for general information about the dashboard designer.
Adding a Dashboard Title
To add a dashboard Container Title, simply enter the title in the Title field, as shown below. The screenshot to the right illustrates the dashboard container title on top, the report container title on the middle report, and the top and bottom reports with no container title.
Note: Publishing dashboards is not yet supported.
You can choose to display the name of the user who ran the dashboard as well as the date and time it was run, as shown at the bottom of the screenshot to the right. This provides the user context for the data you are viewing and the time it was relevant.
Uncheck the box next to "Show run/published as and date information at bottom" if you don't want this information displayed.