Brilliant work for the ANAR Foundation who handle the main child abuse helpline in Spain. The work uses lenticular printing to show 2 message on a street sign billboard, one aimed at adults (generally taller), and a second hidden message for kids (shorter).
If the person viewing the ad is under 1.3m (such as young children) then they will see the hidden message showing bruising on the child’s face in the poster, along with ANAR’s hotline number and copy that reads, "If somebody hurts you, phone us and we’ll help you." People taller than that—i.e., most parents—just see the child without the bruise and the line, "Sometimes child abuse is only visible to the child suffering it."and image on who to contact if someone is hurting them and they need help.
Work by Grey, Spain