The goal for this contest is to make a diptych-type entry, with two of the same photos at first glance. Your job is to alter one of the images in subtle ways, by adding or removing various objects. Merge both your images in 1 big image... the unaltered one on top, followed by the one with the changes.
Other people can guess in the comments where the differences are. Changes can be for example: a missing object, replaced objects, a color change on a certain part, gradient changes, ... Try to make big changes, which are still hard to spot.