The most common cause of people showing websites inside a Macbook is that the graphic designer is using a Mac and Apple provides some pretty nice high resolution tiffs of all its products.

To be fair, would most people know what super-shift-P means?

That said, it would be fairly simple to have a variable for super that resolves to ctrl/cmd on other platforms, the same way that most download pages nowadays infer your platform and show you the binary you most likely want.

If you're writing software, you know what the super key is.

I... I do?

It's the one you put the tux or beastie sticker on.

I've always wanted to show mockups in alternate non mac devices, but they tend to be ugly.

Are they? Really? Apple made you think that they are ugly, while not.