As a test, you need to draw a concept of three characters in a specific style.
The characters must match the characters in the pictures in the app. Also, in the attachment there is a presentation of the concept of the cartoon and a construction guide.

It is worth paying attention to the color and thickness of the line on the proposed options. It is also worth showing each character in at least two active dynamic poses (line of action).
You need to portray a backpack character (bag / suitcase / clutch / chest): a fashionista girl, a pirate, a hipster, an evil old man and someone else of your choice. It is not necessary that there are obvious clues in the design that it is a backpack or a bag. But if such elements are present, that's good.