Postcard!
"A Day in Highland Park"
Conceptual: This postcard is both longer and thinner (in terms of ratio) than a normal postcard, and the reason is to allow a progression and to capture aspects of a moment more than just to show a picture. A postcard like this could be one that is purchased, or one that is made from a machine. One could write on the post card, or one could send it without anything on it - the point is to receive the images, not the post card. The images provide the personality and personalization.
Absent of any text, this post card is also representative of a moment of time, with both front and back two different perspectives on the same scene.