Something I didn't anticipate when I first designed Decker, but which I find delightful, is the way that developing and testing contraptions inevitably seems to produce little clumps of bits and pieces, notes, and one-off tools strewn across cards like a busy workbench.
I love it when people publish decks that have "backstage areas" revealing how things were built, with random leftovers and hidden state and maybe even unfinished todo lists. These hidden, liminal spaces can be our little secret.