JSFiddle - React, Tailwind, and code Playground

HTML

<img src="https://upload.wikimedia.org/wikipedia/en/d/d4/Mickey_Mouse.png" id="the-image" />

CSS

#the-image {
    width: 120px;
    height: 120px;
    opacity: 0.2;
    transition: opacity 0.8s linear;
}

#the-image:hover {
    opacity: 1;
    transition: opacity 0.8s linear;
}