"Does the child see the friend?"
Translation:Sieht das Kind den Freund?
They both mean the same thing. Since the word 'den' appears before a masculine none (Freund), is is automatically known to be the direct object. It is a matter of which one you want to emphasize. With either one your asking if the child sees the friend, but 'Sieht den Freund das Kind?' might be used to mean that you know the child is seeing something, and you want to know if it is the friend that he/she sees. In English it might be also said like, 'Is it the friend that the child sees?" Both are correct, but which one to use would depend on the context.