I have said before, and I now feel more confident in saying it again: electronic picture books prove just how high tech paper picture books actually are and the conversion from print to digital is way trickier for picture books than for just about any other form. I think Shatzkin’s excellent overview is just more evidence.
Removing the paper element from a novel (“immersive reading” in Shatzkin parlance) does nothing or next to nothing to the content. The same cannot be said of picture books, where the constraints of paper bookmaking are built into the tradition of picture book creation. No novelist drafts for a trim size. Picture book artists most definitely sketch for an aspect ratio, if not a specific trim size. Form and content are damned near inseparable.
I am not in any way saying that there is no place in the world for electronic picture books. I am, however, saying that the transition to digital for picture books is going to look different and it might not even be a transition.