[忍]

There’s a lot of variety to be had in persona icons. Just about any creature or animate object is fair game: animals, moving statues, griffins (popular among teens these days for some reason), steam-powered robots, zombies, aliens, just about anything that can walk and talk. The Matrix protocols will stop you from designing an icon for your persona if it isn’t intuitively a persona, so you couldn’t have an icon that is a dust speck, a Greek column, or a cube, for example. They’ll also stop you from making something smaller than adult-dwarfsized or bigger than adult-troll-sized.

How might an AI's persona look like? Any ideas? Sure it's the matrix so (near) anything is possible, however I imagine an AI's "birth" as they become self-aware is like waking up from a coma without any life experience.

[Ashmire]

Hmm...maybe, being childlike, they might tend to "imprint" as some baby animals do, on the first significant thing that catches their interest?  That's pretty vague, but I could see it working as background story for whatever your choice is, and maybe if you really want to, you could simulate that yourself by hitting a random search button on Google or Wikipedia. Could give some inspiration, anyway.

[Novocrane]

I imagine an AI originating from a pre-existing program would keep the same icon and perform the same functions, at least until they're self-aware enough to reconsider either.

[Marcus]

As there are many types of AI's I'm sure they use many types of Icons. AI that interact with people in friendly ways would probably take an icon that would look human at least for when they deal with humans. But it's a very interesting topic I would be careful not to limit AI icons, I'm sure they can come up with very strange representations.