icon.png can be recreated with the following Lua code: minetest.show_formspec(me:get_player_name(), "form", "size[20,20]box[-0.5,-0.5;21,11;#000000ff]item_image[0,0;10,10;lzr_laser:emitter_red_takable_on]item_image[11,0;10,10;lzr_laser:laser_001]") This displays a rendering of the red emitter and a red laser beam, which can then be manually combined with an image editor of your choice.