Slandewi,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.post{
font-family:'Ubuntu',sans-serif;
color:#111111;
background:#FFFFFF;
margin-left:5px;
margin-right:5px;
border:1px dashed #515151;
border-radius:5px;
padding:10px;
margin-bottom:10px;
}
.post{
margin:70px auto;
position:relative;
height:200px;
}
.post:after{
content:"";
background-image:url(http://savepic.net/8495682.jpg);
background-repeat:no-repeat;
background-size:cover;
position:absolute;
width:30px;
height:28px;
top:-16px;
right:6px;
}
</style>
</head>
<body>
<form action="http://" class="post">
</form>
</body>
</html>