I think that Omar is uncomfortable. In the book, he had to do the chores and go to school. Even though he has no sisters and is the older brother he got to do the work. Some boys he sees like doesn’t like help there sister, but instead just run around and do nothing.
I agree with you it’s like he’s a servant many adults do all the work like getting water in the village but Omar does all the work his friends never help all they do is play and learn like any other kid.