* {
  box-sizing: border-box;
}
body {
  min-height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
}
.image-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(3, 1fr);
  width: 600px;
  grid-gap: 0.5rem;
}
.image-container .image {
  position: relative;
  padding-bottom: 100%;
}
.image-container .image img {
  height: 100%;
  width: 100%;
  -o-object-fit: cover;
     object-fit: cover;
  left: 0;
  position: absolute;
  top: 0;
}
.image-container .image img:nth-of-type(1) {
  filter: grayscale(1) brightness(40%);
}
.image-container .image img:nth-of-type(2) {
  -webkit-clip-path: var(--clip-start);
          clip-path: var(--clip-start);
  transition: -webkit-clip-path 0.5s;
  transition: clip-path 0.5s;
  transition: clip-path 0.5s, -webkit-clip-path 0.5s;
}
.image-container .image:hover img:nth-of-type(2) {
  -webkit-clip-path: var(--clip-end);
          clip-path: var(--clip-end);
}
.clip-ellipse-top-left { --clip-start: ellipse(0 0 at 0 0); --clip-end: ellipse(150% 150% at 0 0);; }
.clip-inset-top { --clip-start: inset(100% 0 0 0); --clip-end: inset(0 0 0 0);; }
.clip-ellipse-top-right { --clip-start: ellipse(0 0 at 100% 0); --clip-end: ellipse(150% 150% at 100% 0);; }
.clip-polygon-center { --clip-start: polygon(50% 50%,  50% 50%,  50% 50%, 50% 50%); --clip-end: polygon(-50% 50%, 50% -50%, 150% 50%, 50% 150%);; }
.clip-circle { --clip-start: circle(0); --clip-end: circle(125%);; }
.clip-inset-full { --clip-start: inset(100% 100% 100% 100%); --clip-end: inset(0 0 0 0);; }
.clip-ellipse-bottom-left { --clip-start: ellipse(0 0 at 0 100%); --clip-end: ellipse(150% 150% at 0 100%);; }
.clip-inset-bottom { --clip-start: inset(0 0 100% 0); --clip-end: inset(0 0 0 0);; }
.clip-ellipse-bottom-right { --clip-start: ellipse(0 0 at 100% 100%); --clip-end: ellipse(150% 150% at 100% 100%);; }