The charts in the Fabric notebook are summarizing customer churn data (retained vs lost customers) across dimensions such as geography, products purchased, age, and tenure. This is describing "what has happened" in the data.
Descriptive analytics summarizes and visualizes historical data.
Diagnostic analytics explains "why" events occurred.
Predictive analytics forecasts future outcomes.
Prescriptive analytics recommends actions.
Since only distributions are being shown, this is descriptive analytics.
References:
Microsoft Learn - Types of Analytics in Fabric
Descriptive Analytics concepts