premise: A little girl gets her picture taken while on the merry-go-round. hypothesis: A girl is on the merry-go-round.
entailment: The little girl would need to be on the merry-go-round in order to have her picture while on the merry-go-round.  A little girl is a girl.  A girl having her picture taken on the merry-go-round must be on the merry-go-round.