Nancy Holt developed Spotlight Mirrorlight and Daylight in 1972 in her West Village studio while exploring ideas central to her Locators, a body of sculptural work she developed between 1971 and 1981. This site-responsive sculpture investigates the different qualities of natural and artificial light, an interest also evident in Locator with Spotlight and Sunlight (1972), and anticipates the room-sized installations Holes of Light (1973) and Mirrors of Light I and II (1974).

Spotlight Mirrorlight and Daylight comprises four circles: a round mirror, a circle of light from a carefully positioned spotlight, a circle of reflected light, and a circular aperture in a covered window. The spotlight casts a circle of light around the mirror, creating a luminous ring. The mirror then reflects the projected light onto the wall, forming a circle above the aperture cut into the window.