Have you ever picked up a bag of peanuts, read the text that says 'warning: may contain peanuts,' and wondered who messed up so badly that it became necessary to put that warning there? You're looking at one of those people right now. Everybody knows that putting a plastic bag over your head is a surefire way to starve yourself of oxygen and die. Everybody, that is, apart from this child's mother.
The issue here isn't just that the child has a bag over its head - it's that it's happening right in front of the mother, and she's just looking past it like it's the most normal thing in the world. Does this happen at home? We have issues with the person who took the photograph in this case as well. Don't just stand there with your phone camera - intervene and save the child's life! When you're done with that get on the phone to the child protection agency immediately and make sure this woman is sent for urgent parental training.