Well you could look at their body language, like, the Goat is looking in a different direction from the camera so something has got it's attention, wether it can smell something interesting like food or it saw something like a mouse, it's up to you. The 2 boys in the picture are looking at the camera, suggesting that the person behind the camera could have said something like, "cheese" or "smile for the photo". The boy in the right looks like he might not have been too happy about the picture however the boy in the left, since he's smiling, he may be happy. Also the boy in the right has his hands together in a kind of close position which could suggest he isn't enjoying what he is doing. The only limit is your imagination. You can come up with a scenario by looking at facial expression or body language. Like if someone frowned at you and just froze. You could interpret that either they are angry at you for some reason or they could be in shock of seeing you.