A key work in the ICA exhibition consists of a pristine white monochrome marked by a graphite cross, centrally positioned between two impressive sash windows (above).
On the wall of an adjoining room Kassay has created a larger drawing (below). A vista between open doors connects the two pieces, integrating the canvas into the wall markings and vice versa so that each becomes constituent in an unconventional diptych.
Partly due to this symbiosis, we read the wall-drawn image as another, complementary cross, even though the doorway negates the space where the intersection of its lines would take place.
An act of completion on the part of the viewer is required to - literally - make this connection; it may also become clear that, given the right viewpoint, the centre of the illusory cross would exactly align with the marked centre of the distant canvas.
Through an exercise which similarly animates the other diptychs on display, we collaborate with Kassay himself in the creation of form and meaning.
Yet complex as this work may seem, there's more to it than even partially meets the eye.
The open doorway, while essentially a void, operates as a highly energetic space, a locus of paradoxical operation in which existence is layered with non-existence - or, to reprise one of Kassay's key thematic conundrums, stasis and movement are simultaneously present.
As we mentally generate the 'missing' pieces of the diptych, we energise the existing, static components; and by overlaying the actual (the crossed canvas) with the perceptual (the absent centre of the incomplete drawing) the crux of the work is conjured, quite literally, out of thin air.
In interview, Jacob Kassay frequently expresses concern with interaction and participation.
On the verge of fame in early 2009, he stated that "Creating events is really important (as)... a reminder that there's a thing to experience in the space."
And asked once why he had deviated from his college major of photography, he made the observation that
"... I get frustrated with the photographs of artworks and how easily transferable they are with the internet.... They're meant to be objects that engage the space around them. I'm interested in how people experience work on a very human level."
To illustrate the latter point, Kassay cited the paintings of Ad Reinhardt, "whose work insisted on real-time experience. I wanted to make sure that ... photographing my paintings from the front would render them lame."
With the piece described above, Kassay's insistence on producing "objects that engage the space around them" is made absolutely manifest, its performative and participatory nature stealthily underlined by a title which itself requires decoding: Xanax, or 'X an(d) a(n) X.
Photographs of the work do indeed appear "lame" compared to direct experience of its quietly immersive presence, but what if we fail to detect its enriching subtleties? Kassay provides other clues - and further complexities - to a reading of Xanax.
A film programme selected by the artist to accompany the ICA exhibits included his own Helicopter, shorts by contemporaries such as Amy Granat, and Michael Snow's structuralist classic, Wavelength (1966-7).
Considered a landmark in experimental cinema, the film records a sporadic series of actions occurring in a single room, the fixed position of the camera almost imperceptibly zooming in to a photograph of waves fixed to a wall between two windows (above).
In a mise-en-scène that shares striking similarities with the ICA's own repurposed room and tall, multi-paned windows, Snow's movie makes a protagonist of architectural space, forcing viewers to partake in a concentrated act of observation as it progresses to its final focus on a point that roughly approximates the position of Kassay's crossed canvas (below, top).
And at the opening of the ICA show, a performance by Rhys Chatham also took place in front of this work (below, bottom), his minimal trumpet loops adding yet another layer to the dizzying conceptual confluence of sound waves, sightlines, photographed waves and W/wavelength/s.
X marks the spot, the point at which we need to start digging beneath the surface. Kassay is fully aware that the trickier he makes his treasure hunt, the greater our sense of reward.