I'm somewhat dubious about that for icons with actual recognizable pictures, but a lot of icon attempts today are stylized to death, with just a line, bent and broken in a couple places and maybe if you're lucky juxtaposed with the occasional dot. If there's no text description even on mouseover (or touchscreen, with no cursor...) discovery is more or less trial and error (or perhaps more akin to Russian Roulette if the permissions involve being able to do real damage). Scratch your head and hope there are existing support questions searchable about what on Earth the programmer could have meant to convey...