They can vary greatly. Sometimes, they might show relief or exhaustion. Other times, there could be a mix of emotions like contentment or even confusion.
Start by sketching a basic shape of the mouth. You can make it a simple oval or a curved line. Then add details like lips and teeth depending on the style you want.
The reason could be various. Maybe it's to show how intense the fear is or to emphasize the challenges the kids are facing. Sometimes, it's just for visual effect to make the scene more captivating for viewers.
The cartoon building with eyes might have a curious expression, as if it's constantly observing its surroundings. Maybe it has big, wide-open eyes to show surprise or wonder.