A cornice is a lump of snow that protrudes from the roof after a snowstorm. If you leave it as it is, it will fall off when the temperature rises. If there is a person under it, it will lead to an accident, so it is necessary to save it as soon as possible.
If the amount of snow on the roof increases, the roof will dent or break due to the weight, so it is necessary to remove a certain amount of snow.