The first image contains a button, which is hidden until you press it. Once you have found this button you go on to the next image. The second and all further images contain two buttons, the turquoise one to go forward to the next image, and the red one to take you back to the first image. You are to find all the turquoise buttons on all the images and remember their location to complete an entire level. If you accidentally press the red button, keep in mind its location to find the turquoise button more quickly next time. The harder the level, the smaller is the button that you are looking for.