It’s interesting to draw with simple lines and yet still try to capture character. Things like the size of eyes, the shape of a chin, the direction to draw lines to indicate where and how hair is growing. Nose shape, mouth shape, thin lips, large eyebrows….
Can you tell the emotions that characters are feeling from a drawing? It’s hard to say… Can you tell if the people are male or female, or young or old? Can you show how big they are, what they weigh?
I think you can tell a lot from line drawings if you try.