Reviving this old thread on picture books to add a link to a recent WSJ article which may be of interest -

“The Secret Power of the Children’s Picture Book”,
Even infants get profound cognitive and behavioral benefits from sharing a vivid story
by Meghan Cox Gurdon
Wall Street Journal
January 18, 2019

The subtitle of this article reminds me of the benefits of reading to (and conversing with) the very young.
Related information in an old post (Oct 2014).

In keeping with the theme of the OP, adding a link to a discussion thread on high-level picture books, for elementary-age students: Using Picture Storybooks to Teach Literary Devices.