Reflect shows all the topics in your inventory related to the main subject, along with additional information, including Other Pages. This number shows how many pages, including your top ranking page, cover the topic.
Click on it to open a list of these pages.
That list is identical to the one in inventory (accessed by clicking the same topic in Topic Inventory). It shows all the data available for each page as it relates to that topic — use this to evaluate your alternatives for optimizing.
If a page ranks in the top 20 you can click Competitive Heatmap in the left navigation rail to see its Content Score (how well that page covers the topic).
If it doesn’t rank in the top 20, or not at all, right-click on the appropriate row and select Run in application > Optimize to calculate the content score.