Events Widget doesn't look the same?

Hello,

I just started using your plugin and was particularly pleased with the appearance of the Events Widget (or what I assume is the Events Widget), which has a little color-coded graphic with the date to the left of the event listing. However, when I put this widget on my page, it doesn’t appear the same way at all, instead just listing the event name and date in text form.

Any reason why mine doesn’t look like the one in the demo?

https://wordpress.org/plugins/event-organiser/