JSFiddle - React, Tailwind, and code Playground

HTML

<h1>画像のURLあり</h1>
<img src="https://picsum.photos/200/300">

<h1>画像のURL無し</h1>
<img src="hoge">

CSS

img:after {
    content: "foo";
    display:block;
    width:100%;
}