A few complimentary comments later, it works. And to try to keep his balls off the glass this time. Meg the Cyberdog did it to produce binary code in a shape that confused Art. Amir continues with the prank anyway, in spite of the protests of a beleaguered Jake. Brandy tells him that he'll break the glass. One Wapsi Square guest strip featured Bud and Brandi doing this as part of a failed employment montage.
A few complimentary comments later, it works.
In Sequential Art it's implied that Pip did this with Art's scanner. High-level butts are formidable opponents, and a great way to powerlevel early in the game because they never get to attack first. Re-used wholesale for the UK launch of the product, with a locally-relevant box comped in. Variant in book 2 - while at the Museum of New Inventions, Blork finds what appears to be an ordinary copy machine in one room and starts making faces at its side which is as reflective as a mirror. And then he shows it to every bellboy at every swanky hotel in Central City to find where she's staying.