As others have said, it depends on location. Where I live in the US, the crosswalk won’t turn green for pedestrians unless the button was pushed. If it’s an intersection where traffic primarily flows on one street, and the traffic lights only change when the occasional car from the other street, the traffic light will never tell traffic to stop, and your crosswalk will never turn green. You have to push the button to signal the lights to change.

I think it’s supposed to say, “No Enviting Harassment”, like they don’t want you to envite that kind of behavior here.