Sums it up. Most interesting is that more teenagers tend to know what an icon is used for on the computer than what it originally represented. Which makes total sense because they grew up with these icons.

So it might make more sense to ask "to what degree are people used to this icon?" rather than "how many know where this icon came from?".

In this sense, changing established icons (like I would argue the photo app's one) doesn't seem such a good idea.