The Mobile Layout option allows you to create a version of the report that's been optimized for mobile devices. This is the same interface as the Desktop when we're using the Phone Layout option in the View tab of the ribbon. Existing report visuals are presented in the VISUALIZATIONS pane and you can drag and drop visualizations to the mobile layout canvas, as shown in the following screenshot:
Once in the Mobile Layout view, you can page through the report to create a mobile version of each page. To switch back, click the Web Layout link in the ribbon.
The rest of the ribbon functions, and the editing experience in general, mirrors the editing experience in the Desktop. However, not all of the editing features of the Desktop are included in the Service. Most noticeably, there is no access to the underlying data, data model, or relationships. Hence, there is no way to create new columns or measures. To exit edit mode, click Reading view in the ribbon.