Power BI Desktop supports mobile authoring from 2016. Mobile authoring allows report creators to create report layouts optimized for phones. In the Power BI Desktop June release, Microsoft has delivered a major update for mobile authoring. Find the list of new features below.

New emulator:

• The phone emulator now represents modern devices.
• The old grid has been replaced with a fine-grained grid. Every square of the old grid is now divided into nine smaller squares, giving you more flexibility in placing and resizing visuals.
• The new grid is longer, enabling you to add more visuals to the page.

Updated Visualization pane:

• You can find your desired visual by looking for its name.
• A new visibility indicator allows you to differentiate between hidden and shown visuals.

Overlaid visuals:

Today, the ability to overlay visuals makes it possible for you to use the same design techniques you use in web layout to create beautiful, interactive, mobile-optimized reports.

• Overlaying visuals on top of an image.

Source: Microsoft