let randomLimit = 3;

​

function setup() {

  createCanvas(400, 400);

  angleMode(DEGREES);

  rectMode(CENTER);

  noLoop();

}

​

function draw() {

  background(255);

  let rectSide = width/GRID_SIZE;

  // background(220);

  for (let i = 0; i < GRID_SIZE; i+= 1) {

    for (let j = 0; j < GRID_SIZE; j +=1) {

      push();

        translate(rectSide/2 + i*rectSide, rectSide/2 + j*rectSide);

        rotate(j*random(-randomLimit,randomLimit));

        rect(0, 0, rectSide, rectSide);

      pop();

    }

  }

}