This shows one aspect of how babies think and learn very nicely. Babies use a lot of trial and error, and a kind of statistical analysis. If something works one time with one sort of thing, they will test it out on other things to find out if it is generalisable. So - first it seems that shiny A4 shaped things with pictures on them all allow you to move the pictures around if you swipe with your fingers. But further testing proves this to be untrue.
So the baby doesn't actually know about magazines and iPads. But she is not a blank slate: she has great systems for testing out hypotheses and working out the boundaries of concepts. From this sort of testing out, comes the ability to categorise. iPads, and things that are not iPads, for example.
There is another interesting example of how the brain actively constructs in the new Oliver Sacks book, The Mind's Eye. Except here Sacks is writing about how we don't just "see" the world, but we construct an idea of the world from the data our eyes give us, along with other brain activities.
Sacks has recently developed a scotoma, or blind spot. But he finds that often his brain will "fill in" the gaps of what he cannot actually see. Sacks writes: "if I stood two feet from a brick wall, my scotoma would turn brick red in color, but with no detail. If I stood twenty feet away, it would be perfectly respectable-looking brickwork. Whether the brickwork was exactly the same as the original I could not be sure, but it was good enough to form a plausible simulacrum of the "missing" wall ... I started to think of my visual cortex not just as a rigid duplicating device, but as an averaging device, capable of sampling what was presented to it and making a statistically plausible (if not photographically accurate) representation of it."
Although I enjoy the idea on the YouTube video that the baby thinks the magazine is a broken iPad, I would interpret it differently. I think the baby tries to assimilate all those shiny A4 sized things with pictures to a single concept. But she cannot assimilate them all. Some fit - but others don't. So she must change the structure of her thinking and create two concepts: shiny, A4 things that are iPads, and shiny A4 things that are not.
It is hard work, having to accommodate your thinking to the unexpected. As adults, we know the frustration - in your own car, you pull the knob to turn the headlights on, but then you hire a car on holiday and you are pulling and cursing only to find that this time you have to twist the same-looking knob.
So it is no wonder the baby gets cross. In fact, crossness and temper can often be signs that young children are struggling with something hard in their thinking, and maybe about to make a breakthrough - not simply being bad company and awkward.
All respect to Steve Jobs, but the iPad has come, and it will go - but the baby's "operating system" is powerful enough to keep dealing with an ever-changing world.
For a useful, brief discussion of the meanings of assimilation and accommodation see Piaget and Cognitive Development
With thanks to Gill and Marion for putting me onto this.