Blown highlights

When a sensor takes more light than it can record in a region, everything above that ceiling records identically. A window becomes a white rectangle. A face lit from the side loses the shape of a cheek. Unlike a shadow that is too dark, no information sits under the surface, so lifting exposure in the grade only produces grey. Cameras warn you in two ways: zebras stripe the areas approaching clipping, and false colour maps exposure levels onto colours across the whole frame. Small blown areas such as a lamp or a bright sky are normal and usually fine. Skin is where it hurts.