[thebigpicture]

I think icons can be arbitrary. That's because I've seen some that are so obviously idiosyncratic to the developer; they bear no relation to the function that I can decipher. Some of them I can't even tell what the heck they are. "WTF is that supposed to be?" It's like your example of the floppy. It's a rectangle. It means save. Does it matter if no one even knows what the heck the icon is supposed to represent? If it's not intuitive? For the first few minutes perhaps until I figure out what the program it represents actually does it matters. Maybe it gives me a clue maybe not. From then on, once I figure it out, it's irrelevant.

This is one of the 1001 reasons I think GUI's are a waste of time. I can just as easily tell a user to hit a particular key (i.e. a tactile button) or type "save". Goodbye ambiguity.

Are icons metaphors? Or are they just symbols?

I am not a linguist but I think that you may be stretching the definition of metapahor if you are thinking of icons as themselves being metaphors.

What is an icon? A button with a superimposed symbol?

Now, if you are saying buttons on a computer screen (which do not necessarily need any symbol superimposed on them to work) are metaphors for physical buttons, e.g. like your example of radio buttons, then that seems a little more reasonable.

I've seen early TV remote controls, 8-tracks and various other old things having push-in buttons just like car radios. I'm not sure car radios were the first to have these. Maybe early radios, before TV, were the first to have push-in buttons (or whatever the proper name for them is)?

[UnFleshedOne]

Typing "save" is very far from being unambiguous though. Should it be "save", "store", "write down", "file away", "preserve" or another one of a few dozen ways an unsuspecting person could come up with? Should you type "please" too? At least with GUI there is a button that semi-obviously can be clicked, even if it is unclear what it does. Discoverability is way better with GUI.

[thebigpicture]

What you find ambiguous may not align with what others find ambiguous. You, as a nerd, know there are many options that "save" could entail. Does everyone else know that?

What if a user has no idea about "save options". To them "save" might just mean "save". That is, they want to be able to retrieve it later.

If I say to you "Jump!", you might ask "How high?" Others might just jump. Should we enlist some participants in a study and see what most people do? Let's ask people what "save" means. Then let's show them a button and ask them what it means.

Why does some software have an option to "show button text"? Why would anyone want to see text on a button? Why would anyone want that?

I wish there was a way I could post to HN in a series of buttons, like hieroglyphics. It would be "way better" than using words. You could click on them and they would bounce up and down. Way better than reading.