Its not the best quality – but you get the idea.
A large number of improvements, and some new things.
The main change was in the interaction paradigm. With 1.2 and earlier elements (objects, lines, arrows) were surrounded by a halo. Controls hung off this halo and you could manipulate the element – its attributes, duplicate, delete it etc.
Much of this halo was disposed of, because in busy Napkins it was really hard to accurately select things to move or edit them. The delete and duplicate of elements and the locking and branching of arrows is now in a menu, which you access by tapping once more an already selected element.