I agree, I was very surprised that he doesn't even mention the "hourglass". It's true that it's less and less frequent but I would argue that it's more common than the floppy disk.
I chuckled when I read your post, because at TripAdvisor we have one in every meeting room. And they actually get used.
While "hourglass" may not be a commonly known term, I would imagine plenty of young kids still recognize it thanks to boardgames that involve them. Well, I hope plenty of young kids play boardgames, anyway.
Good one, hourglass, pointer arrow and filmstrip were all obvious ones I missed.