The canvas size where your ZIP package is displayed depends on:
The device orientation
Whether the SideBar is hidden or not
In SharePlus, you can switch between a visible or a hidden SideBar. Because of that, a section of the canvas is always reserved for the swipe gesture that displays a hidden SideBar. That section consists of a 20 px width column located on the left side of the canvas and it is highlighted in red in the images above. Take into account that SharePlus cannot process gestures within that reserved section.