JSFiddle - React, Tailwind, and code Playground

HTML

<div id="picture">
      <img class="content_pic" src="http://nothingmagical.com/assets/coins-icon.svg" alt="exemple"/>
      <img class="content_pic" src="http://nothingmagical.com/assets/coins-icon.svg" alt="exemple"/>
</div>

CSS

#picture {
text-align:center;
}

#picture img {
width:40%;
height:40%;
border:1px solid #000000;
display:inline-block;
margin-left:0;
margin-right:0;
opacity:0.4;
}

#picture img:hover{
opacity:1.0;
}