The pencil case usually has two purposes: to insert a writing or drawing tool.
We can divide between handwriting and drawing in order to work in a more concise working environment.
To do so, I put a switch to drive the user's behavior. It is to indicate whether the pencil case is in writing mode or drawing mode. 

Choose which one of two pencil case is a handwriting mode pencil case for writing, or drawing mode pencil case for drawing.
An ordinary and identical object can have different properties depending on the user's intention.