Who do the shadows belong to?
What do you know about these people? What can you infer?
Are they a couple?
How old are they?
Are they happy?
Who is he on the phone with?
Who are the people in the picture on the...
Who are these people? How are they related?
Which one of them is going to go through the tunnel? How do you know?
Has one of them come from the tunnel?
What do their facial expressions tell you about how they're feeling?