How does the Power BI Playground render the mobile view for their example report in the web browser?

HI Anonymous,

As you said, the ‘layoutType’ property is used for power bi mobile app instead of used when acces from mobile web browser.
If you want to show the mobile layout when you view from mobile web browser, you can create a separate report specifically designed for mobile devices, with optimized visuals and layouts for smaller screens.

Optimize visual formatting for mobile layout - Power BI | Microsoft Learn
After these, you can embed this mobile report to your web application or website when users to access on their phones. (e.g. use JavaScript to check device resolutions and switch to that page)

Regards,

Xiaoxin Sheng