Screen mapping
Screen is the default: each point on the iPad matches a point on your Mac display, like pen mode on a pen tablet. Touch the top-left of the iPad and the pointer jumps to the top-left of the screen.
Keep shape
With Keep shape on, the iPad draws the active area with the same shape as your display, so circles stay round and strokes are not stretched. You will find it in the iPad's mapping panel and in the companion's Settings.
Mouse mapping
Mouse: the Pencil moves the pointer from where it is, like a trackpad. Handy on large or multiple displays.
Related
Still stuck? Email support@deuspen.com with your iPad and computer models, the app you draw in, whether you were on the cable or Wi-Fi, and what you expected. The Diagnostics panel in the companion's Settings shows the connection state in words; tell us what it says.