JSFiddle - React, Tailwind, and code Playground

HTML

<div class="caixa">
    <img src="http://i.stack.imgur.com/CMoaX.jpg">
</div>

<div class="caixa">
    <img src="http://i.stack.imgur.com/lIkte.jpg">
</div>

CSS

img {
    max-width: 100%;
    max-height: 100%;
}

.caixa {
    height: 180px;
    width: 180px;
    background-color: #C8ECFF;
    border:2px solid #717171;
    margin-bottom:15px;

    /* Centralizando imagens */
    display: flex;
    align-items: center;
    justify-content: center;
}