Which feature in Power BI allows users to see additional data when interacting with visualizations?

The feature that allows users to see additional data when interacting with visualizations in Power BI is tooltips. Tooltips provide supplemental information that pops up when a user hovers over, clicks, or interacts with certain elements of a visual. This capability is essential for enhancing user experience by enabling viewers to access critical data points without cluttering the visual with too much information at once.

For instance, if a user hovers their mouse over a bar in a bar chart, a tooltip can display more detailed metrics related to that specific data point, such as exact values, percentages, or even context from other related fields. This interactivity improves the viewer's ability to gain insights and understand the data's context more deeply without navigating away from the primary visualization.

In contrast, drill-through allows users to navigate to a different report page that provides more detailed information based on a specific data point, but it involves a more significant action than simply viewing a tooltip. Bookmarks are used to capture the current state of a report page, including filters and selections, and data alerts notify users when certain thresholds are met, but neither provides immediate detailed contextual insights directly linked to interactions with visual items as tooltips do.