Monitor calibration
Hold a real credit card against the screen and drag until the box matches it exactly (ISO/IEC 7810 ID-1: 85.60 × 53.98 mm). Then set how far your eye is from the monitor. Until this is done, 1:1 and eye-match are guesses — everything else is unaffected.
Drop an image or video onto the wall
SQUINT downsamples your content to the wall's real native grid, draws the physical LED gap, then filters it through the eye's 1-arcminute acuity limit at the viewer distance you set. Nothing leaves this machine.