how to optimize the system

first select the the people
rotate the people 180 degrees
mirror them so they face each other
put each on a different layer

create a folder
give the folder a name: "Them"
move the people into this folder
move this folder below the "sky" layer and above the "ground" layer

open the folder

adjust the contrast so that the people are stronger against the background

create a new layer "sun"
move this layer above the "sky" layer
use the paint bucket to fill the window with a yellow color

add trees and plants

apply the motion filter

print