What is meant by 'Bruno and Gretel treat Maria differently the boy in the striped pyjamas?

In "The Boy in the Striped Pajamas," Bruno and Gretel's differing treatment of Maria reflects their contrasting attitudes towards social class and authority. While Bruno shows kindness and curiOSity towards Maria, a servant in their household, Gretel adopts a more dismissive and superior attitude, influenced by her growing alignment with Nazi ideology. This disparity highlights the innocence of childhood versus the indoctrination of societal norms, illustrating how familial and social influences shape their perceptions and behaviors.