What looked like chalk was on the ground next to a...

What looked like chalk was on the ground next to a large white wall and a ladie which looked like a worker came running over and yelled in the face of a mother of a young child that picked up the stuff that looked like chalk and mite of marked the wall where the art work was and to a child the art work looked like a scribble on the wall, just thinking out loud why didnt they put up signs like do not touch. This was very disappointing of the art gallery