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.”