This is a very generic and almost “standard” pose, for lack of better words.
This is what I call “loose and rough-doodle-practise.”

Sketching this is analogous to a musician practising scales.
It loosens the fingers.
And of course, it’s fun. It has to be, why else would one do it?
I love how the new tablet is pressure sensitive as per the previous iterations of the Samsung range, but they refined the way it really resembles drawing on paper.