From my initial story idea I decided to cut down the beginning of the story to remove one of the 3 characters and focus more on the magic of the letter and stamp that opened the portal to this other world.
I also decided via my feedback to develop my post office character as being mechanical like a little robot sorting out letters in this magical post office sorting world.
With a wise Wish-maker meditating in another world, before the letter arrival as a sort of magical creature. I struggled with the design of the Wish-maker and decided to experiment with many different options.
Picking from each of these characters the elements that stick out to me, then to develop a stronger final design.