Could it be that the great Mexican architect Luis Barrigan created a study with an unexpected, roughly-painted rather expressionistic trompe l’oeil window to brighten a windowless space? It LOOKS that way in this image we found at Aqqindex. It got us casting about for abstract optical illusions we might employ at home, the opposite of the usual trompe l’oeil that tries to create the most realistic illusion possible. We found some very cool ideas.
At the London Design Festival 2015, Studio Toogood created an autobiographical “drawing room” filled with furniture, clothing and personal objects that were, literally, drawn onto big swaths of canvas. Although the rendering is rough, the perspective is realistic. There are a lot of elements we love…
…especially, the staircase, the cracked open casement window and the rug, which appears to be ripped, drawn-on canvas…
Artist Damien Gilley creates complex optical illusions from strips of colored tape. The illusion below gives something of a blueprint for how we might do it in our own space by just taking one or two elements

For years we’ve been mulling creating the illusion of a higher ceiling in our rather low-ceiling space. What if we applied Gilley-esque shapes to the ceiling to open it up…
The rectangular frame around these classic trompe l’oeil clouds would do the trick…

…as though we envisioned Barragan’s seemingly-painted window as a skylight…
Damien Gilley image by Mark Woods Photography
This is the counter example for the duct-tape doorbell cover. It disguises the stairs so thoroughly that someone is sure to fall.
https://i.chzbgr.com/full/8567754240/h861586DA/