You can create visually rich report tooltips that appear when you hover over visuals, based on report pages you create in Power BI Desktop and the Power BI service. By creating a report page that serves as your tooltip, your custom tooltips can include visuals, images, and any other collection of items you create in the report page.
https://docs.microsoft.com/en-us/power-bi/create-reports/desktop-tooltips?tabs=powerbi-desktop
Enhance user experience with visuals embedded inside tooltips giving users a drilled down view of the data.
https://www.youtube.com/watch?v=cGpBUJpFWrM
Tooltips in Power BI are a simple feature that is often underutilized. If leveraged correctly, they can give your reports and dashboards that extra oomph your users didn’t even know they wanted. The purpose of this blog is to not only show you how to set up standard tooltips but also to show you how to create tooltips that take your reports and dashboards to the next level by adding an extra layer of context.
https://www.phdata.io/blog/how-to-make-the-most-of-power-bi-tooltips/