The hard part here is making an image disappear twice over. Each disc on its own has to read as pure noise, yet the pair must agree cell by cell once aligned. The maker handled it with two black plates covered in grids of tiny windows, exactly one open in every neighbouring pair, chosen at random. Where light should pass, the matching cells line up on both plates; where it should not, the openings sit opposite and the light is blocked. It is visual cryptography in plastic form, and a Python script generates both plates from a matrix input, which strikes me as the right tool for the job.
The structure is simple: a body, a diffuser and a bottom cap, all printed on an X2D with a 0.4 nozzle. Inside sits any 38 mm LED tealight as the light source. The lamp reads as a translucent white cylinder with ridged black caps at top and bottom. Ten designs come with it, from a Jack-o'-lantern to an alien, each offered in 0.4 mm and 0.2 mm versions. Lining the cap's notch up with the rim mark turns the static into a lit pixelated picture; a turn of a few degrees throws every pair of cells out of step and the noise returns.
The finer option looks like the winner to me: the 0.2 mm discs carry a 50 by 50 grid on 0.1 mm layers and come out noticeably sharper than the 28 by 28 grid at 0.4 mm. Those thin layers are the price for that extra resolution, in my view. One open question remains around custom art. The maker has said image-to-matrix processing is not really doable in OpenSCAD and has asked for suggestions, offering to put in the time. Personal pictures would suit this design beautifully, and I hope a workable route turns up.