<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="box" id="mybox">
<img class="myimg fill" src="https://placeimg.com/640/480/nature" alt="" >
<div class="uncover">
<div class="uncover_slice"></div>
<div class="uncover_slice"></div>
<div class="uncover_slice"></div>
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/latest/TweenMax.min.js"></script>
<script>
var slices = [...document.querySelectorAll(".uncover_slice")];
var tl = new TimelineLite();
tl.staggerTo(".uncover_slice", 1, { height :"0px"}, 0.2 );
TweenMax.to(".myimg", 1, { scale: 1.2 } );
</script>