JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
    
    <img src="http://placekitten.com/300" />
    <div class="tophack"></div>
</div>

CSS

.box{
    box-sizing: border-box;
    position:relative;
    border:3px solid white;
    overflow: hidden;
    background:green;
    width:300px;
    height:300px;
}

div img {
   transition:.2s all;
   position:absolute;
   left: -3px;
   top:-3px;
}

div img:hover{
    filter: blur(2px);
    -webkit-filter: blur(2px);
    -moz-filter: blur(5px);
    -o-filter: blur(5px);
    -ms-filter: blur(5px);
}

.tophack{ 
    background:white;
    width:300px;
    height:3px;
    z-index:10;
    position:absolute;
    top: 0px;
}