Yeah I had that same confusion initially. I guess they differentiate it as follows: - It's the full photo data (12 MP) for each frame - It captures 1.5 second

Yeah I had that same confusion initially. I guess they differentiate it as follows: - It's the full photo data (12 MP) for each frame - It captures 1.5 seconds before and after you press the capture button - (Speculation based on a dot-point in the keynote) It's stored using some frame-to-frame compression thing, probably similar to a movie but with the option to recover any individual frame as a full size, full quality image I reckon much of their photo technology comes from their acquisition of the SnappyCam app and that developer's custom JPEG encoding.