JSFiddle - React, Tailwind, and code Playground

HTML

<div class="imagen_post"></div>
<div class="imagen_post_2"></div>

CSS

.imagen_post{
   width: 350px;
   height: 350px;
   display: block;
   background-image:url(http://www.hdpaperz.com/wallpaper/original/windows-8-wallpapers-2560x1600-2311_1.jpg);
    background-position:center center;
   -webkit-background-size: cover;
   -moz-background-size: cover;
   -o-background-size: cover;
   background-size: cover;
}
.imagen_post_2{
   width: 350px;
   height: 350px;
   display: block;
   background-image:url(http://www.hdpaperz.com/wallpaper/original/windows-8-wallpapers-2560x1600-2311_1.jpg);
    background-position:center center;
   -webkit-background-size: 100% 100%;
   -moz-background-size: 100% 100%;
   -o-background-size: 100% 100%;
   background-size: 100% 100%;
}