Surely J.K. Rowling didn't realize she was an innovator when she imagined the magic portraits of Harry Potter's universe. But nevertheless, the feasibility of a magic, animated portrait that can interact with real humans approacheth. Wednesday night Mrs. TAE and I saw Harry Potter 8, or Deathly Hallows Part 2 or whatever the last damn movie was called, and I enjoyed it. The epilogue was awkward and terrible, but the rest of it was tense and good, if a bit (necessarily) brief and topical.
Nevertheless, when I watched HP, Ron and Hermione sneak into Hogwarts through a passage behind a magic, animated portrait of Dumbledore's long-dead sister, I couldn't help but think "animated portraits would be pretty easy and would require no magic."
Animated portrait basics:
1) The first part is a thin LCD screen with sufficiently high resolution to show a nice image. Those currently-sold digital picture frames are pretty crappy. Give me 1080p at least.
2) Using a facial motion capture system, get an animated layout of a person's face as they go through a 2 minute barrage of expressions.
3) Using simple feedback AI, like a chatbot, interact with people when they walk up to the portrait.
4) When no one is "at" the portrait, have the character just sort of go through a repeating animated cycle of...whatever.
Pretty much done. As long as the person viewing the portrait didn't ask something to complicated, the animated portrait could do a decent job of responding. And as chatbots get smarter every day, eventually an animated portrait could pass the Turing test and...well yikes.