<img src="https://picsum.photos/id/1069/200/200" alt="A creature from the sea">

img {
  --w: 100px; /* half the image size */
  
  outline: var(--w) solid #0005;
  outline-offset: calc(-1*var(--w));
  transition: 0.6s;
  cursor: pointer;
  border-radius: 50%;
}

img:hover {
  --w: 0px;
}

body {
  background:pink;
  margin:0;
  height:100vh;
  display:grid;
  place-content:center;
}