‘To practise an art’, Ayrton believed, ‘is primarily to discover one’s relationship with reality. It is an attempt to find what in essence is real, by making images.’ As Brother and Sister shows, ambiguity is characteristic for this reality. 

We wonder what the young boy holds in his hands - is it a little bird? Real or a toy? Is he pointing it in the air as a gun or making shapes out of the shadows cast? We ponder what the story is here? Is she trying to stop him freeing the bird – her hand firmly grasps his arm. We ask where are they? Ayrton’s background reveals nothing of their location. 

By portraying two figures in this painting Ayrton shows us his skill as a painter, portraying the girl at a ¾ angle to us, and the boy in profile. The poses add variation and a sense of dynamics, allowing for the figures to interact with each other. The suggested movement of the limbs seems in contrast to the lineal flat planes with which the faces are depicted. The children seem almost emotionless – their faces fixed whilst their bodies move.