style.css

.imageLink {
  display: block;
  position: absolute;
  bottom: 12px;
  right: 12px;
  width: 36px;
  height: 36px;
  background: rgba(0, 0, 0, 0.6)
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='48' height='48' viewBox='0 0 48 48'%3E%3Cpath d='M14 28h-4v10h10v-4h-6v-6zm-4-8h4v-6h6v-4H10v10zm24 14h-6v4h10V28h-4v6zm-6-24v4h6v6h4V10H28z' fill='white'/%3E%3C/svg%3E%0A")
    no-repeat center center;
  background-size: 90% 90%;
  border-radius: 4px;
  text-decoration: none;
  opacity: 0;
  z-index: 9999;
  transition: opacity 400ms;
  transition-timing-function: ease;
}
.imageLink:hover {
  opacity: 0.9 !important;
}
.imageLink:visited,
.imageLink:link {
  text-decoration: none;
}

.goog-inline-block:hover .imageLink {
  opacity: 0.6;
}

/* TODO: the selection box border blocks the View Image click. Find a better solution without modifynig page styles. */
.docs-squarehandleselectionbox-border {
  display: none !important;
}