This image gallery snippet was designed by Dudley Storey. You see a vertical section where each image is cropped to be a part of a stack when you click on one it slides out to the right and expands to the full image.
If you are having trouble with the pen, try the archived copy on GitHub
Image Gallery Snippet
See the Pen Side-Slide Image Gallery with clipPath and Web Animations API by Dudley Storey (@dudleystorey) on CodePen.0