sample-photo.jpg: the photo the galleries of `coursekit video gallery` draw the pieces that take a photo with.
"Desktop with laptop and calculator (Unsplash)", Wikimedia Commons:
https://commons.wikimedia.org/wiki/File:Desktop_with_laptop_and_calculator_(Unsplash).jpg
Licence: CC0 1.0 (public domain dedication), https://creativecommons.org/publicdomain/zero/1.0/
Scaled to 1600 px wide, without its metadata.
