For both the moments where Cyril is running from the police and ends up in the doctor's office and the opening scene when he's using the phone and won't let go, the young actor was just instructed by the directors not to give up what the character was doing under any circumstance.
According to the Dardenne brothers, the film is based on the idea of "a woman who helps a boy emerge from the violence that holds him prisoner."
The script was structured with a fairytale in mind, where the boy would lose his illusions and Samantha would appear as a fairy-like figure.
This film is part of the Criterion Collection, spine #646.