The problem with "spot the difference" tests, imho, is that I would expect an AGI to be easily spotted. There's going to be a speed of calculation difference, at the very least. If nothing else, typing speed would be completely different unless the AGI is supposed to be deceptive. Who knows what it's personality would be like. I'd say it's a simple enough test just to see if an AGI could be hired as, for example, an entry level software developer and keep it's job based on the same criteria base-level humans have to meet.

I agree that current AI is nowhere near that level yet. If AI isn't even trying to extract meaning from the words it smiths or the pictures it diffuses then it's nothing more than a cute (albeit useful) parlor trick.