title: Does `size` need to be used with `srcset`, what are the pros / cons?
body: <p>Does <code>size</code> need to be used with <code>srcset</code> ? Ive got a site that has a large image pretty much full screen apart from a 50px board all the way round. The proportion of this image dosnt need to change depending upon different screen proportions / sizes. </p>
  
  <p>At the moment im using just <code>srcset</code> like this : </p>
  
  <pre><code>&lt;img 
  src="bath.jpg"
  srcset="bath-large.jpg 1500w, bath-medium.jpg 1000w, bath-small.jpg 600w"
  alt="#"
  &gt;
  </code></pre>
  
  <p>The issue with this is that if a user is on a desktop opens up the site in a compressed browser (so the small image will be loaded) then makes their browser window bigger, the small image will just be scaled so it will now be pixilated. (If they refreshed the page they would now get the large or medium image, but i doubt any one would refresh the page after every resize of a browser window)</p>
  
  <p>By using the <code>size</code> attribute would it then try are recalculate which image to use if the browser window is resized ? If not what is the use case for the <code>size</code> attribute ? </p>