Send a reflection to the wall nearest you. Then send the reflection to a wall further away. The reflection on the wall further away is larger and therefore, the energy more spread out.
I am very confident that you have not tried this for yourself. I want you to show me pictures of this happening (with sunlight); I think you will find the experience educational.
(Edit: The mirror and the wall must both remain at the same rotational angle – if you angle the mirror to move the spot, and the spot becomes elongated because it’s now coming in at a more acute angle, it doesn’t count. Shining a sunbeam on the edge of a doorframe and then through the door to a faraway wall that’s through the doorway would be a good way to do it.)
I am very confident that you have not tried this for yourself. I want you to show me pictures of this happening (with sunlight); I think you will find the experience educational.
(Edit: The mirror and the wall must both remain at the same rotational angle – if you angle the mirror to move the spot, and the spot becomes elongated because it’s now coming in at a more acute angle, it doesn’t count. Shining a sunbeam on the edge of a doorframe and then through the door to a faraway wall that’s through the doorway would be a good way to do it.)