The installation features a sensor-rigged seesaw surrounded by semi-transparent fabric, where visuals are projected as they're created in real-time.
What these visuals end up looking like depends on the approach taken by the audience — for instance, how forcefully they push off the ground or whether they find moments of equilibrium.
They are not given specific instructions but left to explore, discover and strategise for themselves.
The experience is meant to represent the nature of the creative process in a collaborative design team.
Such was the brief from the Design Museum Holon, which initially commissioned and showed Reciprocal Syntax as part of the Conversation Show exhibition in 2019, curated by Maria Cristina Didero.
BCXSY's co-founders, Boaz Cohen and Sayaka Yamamoto, said that in their creative process, they tended to develop their own "intuitive, playful and abstract language" and that the melding of minds made it impossible to trace where the contribution of one person ended and the other began.
"Through a constant stream of exchange and reflections, bits and pieces start falling into place and distinctive patterns and narratives are conceived," said Cohen.
"It is as if a new, correlative universe emerges and encircles us, its creators."
The "universe" as depicted in Reciprocal Syntax is a mountain landscape, which BCXSY said is a nod to Microsoft's once-ubiquitous Bliss computer wallpaper.
The landscape starts off plain and grows richer as two audience members interact on the seesaw, which contains an accelerometer — the same sensor smartphone use to know when to switch the display from portrait to landscape mode or to track a user's steps.
Cohen said that they initially considered using a range of different sensors. They changed their mind when they saw the "extensive depth of data" a single accelerometer could provide, giving them a picture of the speed the riders' were moving and their positioning.
Based on this, they wrote a visual script to generate the audiovisual content in real time.
The riders finding equilibrium is a key trigger. When they are in balance, Reciprocal Syntax introduces new elements, such as clouds, colour gradients and shooting stars.
Their actions then control those elements. For instance, when one of them hits the ground, they "create" new clouds — clouds whose path across the sky reflect the force and speed of the riders.
As a final metaphor, there is a play on perspective. Outside viewers can only see part of the installation, while the riders inside can see everything and are fully immersed.
Cohen and Yamamoto founded BCXSY (the acronym combines both their initials) in 2007 and are based in Amsterdam.
Images are by Klau Rothkegel.