Element has 2 different modes for creating fast rendering reflections allowing objects to reflect each other. Mirror Surface is typically used for ground planes and Spherical for objects reflecting other objects.
To allow your objects to be reflected onto a ground plane, click on the ground plane model and click the Reflect Mode icon in the model settings. Then change the Mode drop down to Mirror Surface.
Select an object and change the Reflect Mode to Sphere and this will allow other objects to be reflected onto the object’s surface.
Disable Environment turns off the reflection of the environment map and will only render other object’s reflection.
Render Self will allow object’s own pieces to be reflected back onto the object. This works best with Sphere Mode.
REFLECTION OFFSET AND MIRROR CLIP
Reflect Offset will move where the object reflects from. For a box object the reflection plane may be below the top plane, you can use the middle value to position the reflection plane, represented by the blue box and 4 arrows, at the top of the plane. Then you can use the Mirror Clip Below Plane option to tell it not to stretch the reflection to the geometry below it.
Set the view Perspective to Front when moving the Reflection Offset to better see the top plane.