In his work Santiago Sierra often addresses structures of power that operate in our everyday existence. Sierra's work intervenes into these structures exposing situations of exploitation and marginalisation, famously hiring underprivileged individuals who, in exchange for money, are willing to undertake pointless or unpleasant tasks. Sierra's work never repeats reality, but challenges it exposing its intrinsic mechanisms. The essence of the work is often in the tension generated and sustained between the event or its documentation and the spectator, who is exposed to what can be described as the formal and poetic articulation of the voice of all those who are normally marginalised or disenfranchised.