There could be various reasons. Maybe she saw something unexpected and is covering her mouth to keep quiet. Or it could be part of her character's mannerism to show shyness or surprise.
Maybe she's sad about something that happened and doesn't want to show it too much.
Perhaps she's heartbroken over a failed relationship or facing a difficult challenge that's overwhelming her emotions, causing her to react this way.
Maybe she's sad about some event or situation happening in Egypt that has touched her deeply.
Maybe the kid is trying to hide a secret or keep quiet about something.
The girl covering her mouth and laughing in the cartoon usually conveys a sense of shyness or trying to hold back laughter.
Maybe it's trying to hide a smile or keep a secret.
Maybe he's trying to hide a laugh or a secret.
It could be popular because it triggers people's curiosity. They might wonder what the kid is trying to hide or why they're covering their mouth. Also, the visual might be artistically appealing.
Maybe he's trying to hide something or stop himself from saying something.
It could symbolize keeping quiet or hiding something. Maybe it represents secrecy or trying to stop oneself from speaking.