     }
 
     epd.update(k_update_no_blink);
+
+    mask <<= 1;
   }
 
   delay(DELAY_BETWEEN_IMAGES_MS);

  int16_t rx = random(w);
  int16_t ry = random(h);

  // Draw stuff
  for (int16_t x = 0; x < w; x++) {
    for (int16_t y = 0; y < h; y++) {
      buf[y * w + x] = (x + rx) ^ (y + ry);
    }
  }

  epd.clearBuffer();
  epd.update(k_update_quick_refresh);

}

void test_image_layers() {
  epd.setRotation(1);

  // Framebuffer
  int16_t w = epd.width();
  int16_t h = epd.height();
