Whiteread's sculptures are casts of carefully chosen objects, most of which bear the traces of human use. She most often casts the 'negative' spaces around these objects, which then become the 'positive' form of the sculpture. Often the objects recall poignant events; her recent group of bed casts can be associated with sleep, illness and dying. This work adds another dimension to the group of bed casts, with its combination of solid sculptural form and associations of air-filled fragility. Here, the mould containing the air mattress during the casting process has become part of the work, enclosing the Lilo within its box-like shape.