godot/editor/icons/ViewportTexture.svg

<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16"><rect width="12.75" height="10.75" x="1.625" y="2.625" fill="none" stroke="#e0e0e0" stroke-width="1.25" rx="1.5"/><path fill="#e0e0e0" d="M9 6v1H8v1H6v1H5v1H4v1h8V9h-1V7h-1V6z"/></svg>