named that way, because this works
have been created "en passant", i.e. during a telephone call.
“....when I’ve been the phone for a long time, I invariably reach for a pencil. Regardless of the conversation and as an accompaniment, I start drawing on any piece of paper that happens to be in the vicinity in an absent-minded way, although a term or a word that someone said can also provide inspiration while I draw…”