<div class="item">
  <img src="http://placehold.it/400" alt="">
</div>

img {
  border-radius: 60px 0;
}

.item {
  width: 400px;
  position: relative;
  margin: 30px auto;
}

.item:after {
  content: "";
  width: 400px;
  height: 400px;
  position: absolute;
  top: 60px;
  left: 60px;
  border: 1px solid #000;
  border-radius: 60px 0;
  z-index: -1;
}