The two elves who, granted, could be human, are (as the title says) slaves. The girl is Tamina and the little kid with the carrots is Tamin. They were born in to slavery and sold off so she had to look after him until he was old enough to stand up for himself. Here though he's still really vulnerable. The guy in the background is just another random slave, but he's much higher ranking than them and he treats them like dirt. Don't worry, Tamin does eventually get revenge and kill him. Done in 6B Sketching pencils.