HTML5: Best Practice responsive for Media

1st Resolution switching <img srcset="elva-fairy-480w.jpg 480w, elva-fairy-800w.jpg 800w" sizes="(max-width: 600px) 480px, 800px" src="elva-fairy-800w.jpg" alt="Elva dressed as a fairy" /> 2nd Art direction #Image <picture> <s...