.right {
position: absolute;
left: 0;
top: 0;
-webkit-clip-path: polygon(0 0, 100% 0%, 100% 23%, 0 83%);
clip-path: polygon(0 0, 100% 0%, 100% 23%, 0 83%);
}
.left {
position: absolute;
left: 0;
top: 0;
-webkit-clip-path: polygon(0 75%, 100% 22%, 100% 100%, 0 100%);
clip-path: polygon(0 75%, 100% 22%, 100% 100%, 0 100%);
}
border {
position: absolute;
left: 0;
top: 0;
width: 400px;
height: 300px;
background-color: black;
-webkit-clip-path:polygon(0 75%, 100% 22%, 100% 28%, 0 83%);
clip-path: polygon(0 75%, 100% 22%, 100% 28%, 0 83%);
}
<!DOCTYPE html>
<html>
<head>
<title>HTML, CSS and JavaScript demo</title>
</head>
<body>
<img class="left" src="https://picsum.photos/400/300?random">
<img class="right" src="https://picsum.photos/400/300">
<border />
</body>
</html>