title: Lazy load-style text as seen on new YouTube design?
body: <p>Can't seem to find what library this is, or anything about it, but I'm seeing it more and more lately. Querying dynamic text via lazyload (with grey bg placeholder). Examples are: cloudflare.com, youtube.com, upwork.com. 
  <a href="https://i.stack.imgur.com/Xo6gz.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/Xo6gz.jpg" alt="enter image description here"></a></p>
  
  <p>Anyone know what it is? Thanks. </p>