It could be that she's expressing excitement or joy in an exaggerated way. Sometimes in cartoons, emotions are shown very intensely. Or perhaps she's in danger and screaming for help.
Maybe she's scared of something shown in the cartoon. Like a monster or a sudden event.
Maybe she saw something really scary like a big monster or a creepy shadow.
Maybe it's for creating a sense of drama or tension. It could be part of a story or just an artistic expression.
Maybe she's scared or in some kind of trouble. That could be why she's screaming.
Maybe she's scared of something or got into a dangerous situation.
It could be that she saw something dangerous approaching the boat, or she's having a moment of panic for no obvious reason. Sometimes people just freak out unexpectedly!
It could be that she's having a fun moment and wants to express her joy by screaming hello. Or perhaps she's in a situation where she needs to greet someone loudly to be heard.
Maybe she's scared of something she saw on the bus. Or she could be having an argument with someone.
The manga girl could be screaming because she's excited or celebrating something. Or perhaps it's part of a dream or a hallucination. There are many possible explanations depending on the context of the manga.
There could be various reasons for the comic girl to scream. Maybe she's being chased, won a big prize, or had a fight with someone. It all depends on the context of the comic.
The manga girl's face might be screaming because she's in danger, or perhaps she's reacting to a sudden shock. It's hard to say for sure without more context from the manga itself.