This Kaleider screen image shows a Triangle (Split) Funnel that has been positioned within a photo.  The size and shell thickness have been adjusted as desired with the mouse.  The two outer triangles indicate the portion of the image that will be the basis for reflection.  The triangle is split vertically so that the half bordered by yellow will be reflected across the red line onto the half bordered by green, creating an effect of greater symmetry.  Just press Render (or the Space bar) to render an effect.  The Shifting Effects feature can then be used to reposition the result as desired with the mouse, essentially re-rendering the same effect based on different relative positions within the source image.