Data visible on Power BI Service

Hello Heinrich 

When you share a semantic model, the recipient has access to all the data in that model, not just the data or fields shown in any particular report visual. Unless row-level security or object-level security is applied, the entire dataset is exposed when someone opens the model for exploration or connects via features like “Analyze in Excel” . They can create new visuals and potentially see columns, tables, or measures that were not used in the original report. If you need to restrict access to certain rows, columns, or tables, you must define security rules in the model accordingly.

https://learn.microsoft.com/en-us/power-bi/collaborate-share/service-how-to-collaborate-distribute-dashboards-reports?WT.mc_id=DP-MVP-5003835

Hope this helps.

thanks