From The Guardian:
Each portrait faces a question in the text. “Have I told you that you are creative?” shows Obama's daughters looking at a girl holding brushes and a palette, who in turn is looking across the page at herself in the future as Georgia O'Keeffe. This image of the painter at work expressively captures the feeling of her artwork, without being merely a pastiche. “Have I told you that you are smart?” shows Obama's daughters again, together with the girl with brushes and palette, looking at a boy holding a pencil and looking across at the mature Albert Einstein. He is dramatically shown on a hill against a starry sky, holding a pencil and notepad, the pages of which are floating away across the rooftops. “Have I told you that you are an explorer?” includes the two daughters with the young O'Keeffe, Einstein, King, Billie Holiday, looking at a boy holding a toy rocket who is looking across at himself as Neil Armstrong walking on the moon.
“He watched the world from way up high
and we watched his lunar landing leaps,
which made us brave enough
to take our own big, bold strides.”
As the book develops, we see all these children linking together, exchanging brushes, palette, pencil, baseball bat, book and set-square as they congregate in one enormous family, which now includes children not featured before: “Have I told you that America is made up of people of every kind?” How I wish he'd written that the world is made up of people of every kind. The last page shows the president walking into the distance holding the hands of his children:
“Have I told you that they are all part of you?
Have I told you that you are one of them,
And that you are the future?
And have I told you that I love you?”
This beautiful illustration reinforces the theme by showing their shadows as being joined together – as if they are one being.
More here.