Tilda Swinton sleeps in glass box at Museum of Modern Art

New York: Actress Tilda Swinton has taken up residence in a glass box at the Museum of Modern Art as part of an unannounced performance piece.

Clad in jeans and a blue button-down shirt, the 52-year-old Academy Award winner slept on an unadorned white pallet in a transparent display case, reported New York Daily News.

A label for the work lists its materials as "living artist, glass, steel, mattress, pillow, linen, water, and spectacles."

Her public napping is part of a performance art piece titled "The Maybe," which she debuted in 1995 at London`s Serpentine Gallery. She later repeated the work in the Museo Barraco in Rome.

Swinton will return to the glass case several times to appear in the installation, but the exhibition dates remain a mystery even to MoMA employees.

"Museum staff doesn`t know she`s coming until the day of. All that`s in the box is cushions and a water jug," a source said.

Each performance will last the entirety of the day that museum is open. Though the box was located on the bottom floor, it may move locations for later dates.