One of the nice new features of Excel Services now available in SharePoint 2013 is ability to interact with pivot tables directly from the browser without having to open the workbook in Excel. Here we have a PivotTable report deployed in SharePoint.
Before, if we wanted to change a layout of the pivot table, we had to click on Open In Excel, make changes and then save it back to SharePoint. Now, if we want to interact with a Pivot Table, we can right click on it and see an option to Show Fields List
Clicking on that option brings up the familiar interface that allows us to customize the pivot table layout