There are a few things which make dashboards useful:
Ideally, the dashboard is a “single pane of glass.” By that, I mean that all relevant indicators are visible on the screen at the same time. With my car, it’s close but no cigar: I can see one of miles traveled, average fuel mileage, or current fuel mileage at a time. If I want to see a different item, I need to hit a button on the steering wheel to scroll through those options. By contrast, the TV show dashboard has everything on a single screen with no scrolling or switching required.
Key Performance Indicators (KPIs) are readily apparent. For the TV show dashboard, we have a couple key metrics on display: episode rating and number of votes as sourced from IMDB at the time I pulled those numbers.
Relevant KPIs are bunched together in a logical fashion. On the top half of the dashboard, we see two visuals relating to average rating by show. The bottom half show rating & user vote counts for the three highest-rated shows.
Layouts are consistent between dashboard elements and between related dashboards. On the TV show dashboard, bars and columns use a single, consistent color. Also, shows have thematic colors: Daredevil in red, Jessica Jones blue, Punisher black, etc. If I had a second dashboard for season two, I would want to use the same theme.
Read on for more details about what a dashboard is and some of the sundry forms of dashboards.