Drop and Box Shadow - CSS

Transparent images use drop-shadow() filter function to create a shadow on the image's content, instead of box-shadow property which creates a rectangular shadow behind an element's entire box.

Icon: icons8.com

DEMO

box-shadow

drop-shadow

HTML

<div class="wrapper">
  <div class="mr-2">
    <div class="mb-1 text-center">
      box-shadow
    </div>
    
    <img class="box-shadow" src="https://img.icons8.com/color/344/money-bag.png" alt="Image with box-shadow">
  </div>
    
  <div>
    <div class="mb-1 text-center">
      drop-shadow
    </div>
    
    <img class="drop-shadow" src="https://img.icons8.com/color/344/money-bag.png" alt="Image with drop-shadow">
  </div>
</div>

CSS

.wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
}

.wrapper img { 
width: 100px;
}
.mr-2 {
  margin-right: 2em;
}

.mb-1 {
  margin-bottom: 1em;
}

.text-center {
  text-align: center;
}

.box-shadow {
  box-shadow: 2px 4px 8px #585858;
}

.drop-shadow {
  filter: drop-shadow(2px 4px 8px #585858);
}