These three children, presumably siblings, are members of the Brahmin or priestly caste, the highest class in Hindu Indian society. They were photographed in Bombay (now Mumbai) India in 1922.
The kids are richly dressed and adorned, and the eldest brother is posed with a book to demonstrate that he is receiving an education. They don't look particularly happy, but photographic techniques at the time required the subjects to sit still for several minutes, so they may simply be uncomfortable or bored.
During British control of colonial India, many missionaries and humanitarians from Britain and other western countries decried the Hindu caste system as unfair. At the same time, the British government in India often was perfectly happy to align itself with the Brahmins in order to preserve stability and introduce at least a facade of local control in the colonial regime.