An in-camera double exposure of a pathway with railing and a forest around it with deciduous trees. The camera is turned upside down at the second exposure, making a mirror of the image and the sunlit part of the railing at the center makes a romb of light with a dark diagonal part across the image from upper left to low right as a tunnel to choose witch way to go. The image is black and white.
https://media.mastodon.nu/media_attachments/files/115/276/139/510/437/057/original/3b1f37b687ebd5bf.jpeg