Summarization is available in the analytic tools for all datasets. Once you've selected a theme and run the summarization it will show more details about the theme. Running summarize may take up to 30 seconds as Thematic generates these results. 

These results should help you better understand the context of the theme and how it's being mentioned. Each result has a volume for number of responses, and an overall sentiment (Displayed by the red or green face). Clicking on a result will show the sentences in the responses related to the result.