Not all picture books are only for the preschool & primary grade audience. Some can be appreciate by a much wider audience. This list includes picture books that will appeal to upper elementary grades or older.
I Dreamt by Gabriela Olmos
Ideas are all Around by Philip Stead
The Journey by Franesca Sanna
The Treasure Box by Margaret Wild
Questions Asked by Jostein Gaardner
How To by Julie Morstad
Why am I Here? by Constance Ørbeck-Nilssen
Bertolt by Jacques Goldstyn