It is very hard for me to believe that Grandma would choose the smaller screen of the old iPhone form factor rather than the bigger screen of the new Android phones.
I doubt that Grandma would be convinced by "but what you want is superior integration of hardware and software". She'll reply "but I can't see the tiny birds on this one. Why can't I get the one where I can read the screen?"
"But Grandma, the iPhone has lots of apps in the appstore besides Angry Birds and it didn't copy the name of the Appstore - Google copied Apple! and you can buy all the newest pop music and TV shows on iTunes! Not only that, but Apple will change the OS for you for 2 hardware iterations because it is not fragmented and if you pay more for Applecare you can talk to Apple on the phone for years! And only poor people who hate Apple get anything else!"
"Huh? I don't understand any of that. I'd rather be able to see the screen better, I think."