createImage and set() - OpenProcessing

mySketch
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var leg;
​
function setup() {
createCanvas(windowWidth, windowHeight);
}
​
function draw(){
bunker();
image(leg, 300, 500);
image(leg, 600, 500);
image(leg, 900, 500);
leg.updatePixels();  
}
​
function bunker(){
  leg = createImage(25, 100);
  background(255);
  leg.loadPixels();
  for (i = 0; i < leg.width; i++) {
    for (j = 0; j < leg.height; j++) {
      leg.set(i, j, color(18, 68, 14));
    }
  }
}