If they hit, it's a hit even though they didn't hit what they wanted to hit, is how I would rule it.
They weren't attacking you, they were attacking a figment (which they hit). That is to say, they chose a target and hit it, the fact that it turned out to be the wrong target is irrelevant. Even if they missed I don't think it would provoke an AoO because they missed the image, not you.
Same thing if they attacked someone disguised as you or an illusion that looked like you. They may not have hit you, but they didn't miss you either because they weren't really targeting you at all.