JSFiddle - React, Tailwind, and code Playground

HTML

<img src="http://placekitten.com.s3.amazonaws.com/homepage-samples/200/140.jpg" />

CSS

@keyframes show {
    to {
        opacity: 1;
    }
}
img {
    opacity: 0;
    animation-name: show;
    animation-delay: 3s;
    animation-duration: 3s;
    animation-iteration-count: 1;
    animation-fill-mode: forwards;
}