You can view CRM.Client in portrait or lanscape mode. Data is always displayed in a single column for landscape and portrait mode. For Details view of a record, data is displayed in two columns for the landscape mode and empty fields are also displayed. While in the portrait mode empty fields are not displayed.
For more information on when the portrait and lanscape modes are displayed, see the Sreen Resolution and Orientation section in Responsive behaviour of CRM.Client Application.