That Tilda Swinton is a little strange should not come as a surprise. But we bet you didn't know she occasionally does a performance art piece where she occasionally sleeps in a glass box at a museum over the course of a month. 

Gothamist's Ben Yakas reports Swinton will be sleeping in a glass box at the Museum of Modern Art in New York City over the course of the next month. "Museum staff doesn't know she's coming until the day of, but she's here today. She'll be there the whole day. All that's in the box is cushions and a water jug," a museum source told Yakas. She's not there every day; it's up to her when she comes. The source added that the box will likely move to different areas in the museum over the course of the month. Today it's near where they take tickets, but tomorrow it could be on the second of third floor. Who knows where it'll be next?! Tilda travels. 

It's all part of a performance art piece called "The Maybe" that she's performed twice before. This is the first time Swinton has performed "The Maybe" in the U.S. She did it for the first time at the Serpentine Gallery in London in 1995, and again later at the Museo Barracco in Rome. 

Swinton was first spotted lurking the MoMA halls late yesterday, but the keen-eyed observers had no idea why: 

And then, as the museum opened today, some reports started coming in over Twitter what was going on: 

People seems excited: 

If you happen to live in New York and don't have plans for the afternoon, you might want to head down to the MoMA and check this out. If you happen to live in New York and have plans for the afternoon, you might want to cancel those plans and go to the MoMA. Come on.

Reuters' Anthony De Rosa said it best: art is weird. Tilda Swinton is the greatest, though.

[Inset via Gizmodo's Sam Biddle]