The ad is hidden from adults, and the message is only visible to children--based on their height and angle of viewing.
To the abused child, they see: "If someone hurts you, phone us and we'll help" with a number to call to get help in an anonymous and confidential way.
To the accompanying adult, they see: "Sometimes, child abuse is only visible to the child suffering it."
This is a great reminder to adults to behave themselves in how they treat children, and a way to get critical assistance information to children discreetly.
Learning from this, I'd love to see a similar campaign here in the U.S. to help child abuse victims, as well as other variations to help abused women, human trafficking victims, and others--by finding technological innovations to help them get the message in ways that their abusers don't necessarily detect and which can't easily be blocked from their victims.
Perhaps, one way to do this is to widely deploy emergency, push button, help kiosks where victims can easily reach out for assistance, where otherwise they would have no way to call for help--such as when their phones, money, passports, and so on have been confiscated.
Their are a lot of people hurting out there and we need to get to them to tell them that there is help available, that they will be protected (and mean it), and that they can easily reach out and we'll be right there for them.
Now that's an easy button to really help people. ;-)