Not all books are conducive to ebooks or epub format. Amazon has focussed on novels or as John Birmingham puts it "the disposable words". There are no images, charts, tables etc to confuse the reading of plain text. When it comes to novels the Kobo, Kindle, Sony and other similar readers are great. When the reader has control of the font and size images in an ebook will change the appearance. You may find the text some spaces away from the image. Don't worry about that as the publisher has typeset the ebook to a certain font size and if you change that then you change the appearance of the page.
But if you want an enhanced experience of picture books, books with images, charts, tables etc then you would need to choose an alternative. It's horses for courses. Apparently 30% of ipad owners have a Kindle.
Be careful when looking at books that talk and move. These are not ebooks but apps. Our Outback Songs picture book is now available as an app from the Apple app store and Android market.