Nice restrained interaction design project by Sebastiaan Pijnappel. Some comments on the design from a Co.Design article:
He [Pijnappel] says he took special inspiration from laying amidst high grass in a park.
“As you lift your head up slightly you can just about see a few people walk by. You see them, but they don’t see you, or at least that’s the sense of security and privacy you have,” he says, “You lower your head back down and everyone and everything is blocked from your sight again. Just as easily, swiping the grass halms aside exposes you, putting you in the same space as them and allowing you to say hi.”