Her is certainly one of the most unusual love stories ever filmed, with Scarlett Johansson as a computer voice and an unrecognizable Joaquin Phoenix as a sort of nerd who falls in love with her, with Rooney Mara and Olivia Wilde in little support parts, and Amy Adams very effective in not much more.
It isn't always clear whether what we are looking at is what is actually happening, what happened a little while ago, or what is going on in Phoenix's mind, but that's not a mistake-- we know as much as we need to, usually as much as Phoenix does, and everything fits both theme and story no matter what interpretation we make.
Phoenix lives and learns (I'm not saying what or how), and while Johansson has no body, she seems to be learning and developing, too. That isn't certain about her, because she is one of those supercomputers I read about that are programmed to fit their owner's thoughts and feelings, and quite possibly to act as a kind of therapist to help their owners overcome their weaknesses, which Phoenix definitely needs help on.
I'm not sure why writer-director Spike Jonze has both Phoenix and Adams going through the plights of divorce. Neither do I know why Phoenix has such a palatial skyscraper apartment with glass walls overlooking vistas of the city, but they're at least beautiful and not particularly distracting.
Just about any interpretation you make of these things will fit the general scheme.
The theme of love physical, and love not physical, has seldom been so clearly presented, and the whole movie is psychologically believable, including its main thematic premise of human vs. machine.
What I read about current robotics suggests that Her may even be more realistic than I credit it with being.