Display associated image of product variant in cart.liquid

cart-snippet.liquid

<a href="{{ item.product.url }}" title="{{ item.product.title | escape }}">
  {% assign found = false %}
  {% for img in item.product.images %}
    {% if found == false and item.variant.title contains img.alt %}
      <img src="{{ img | product_img_url: 'thumb' }}"  alt="{{ item.alt | escape }}" />
      {% assign found = true %}
     {% endif %}
  {% endfor %}
  {% if found == false %}
    <img src="{{ item.product.featured_image | product_img_url: 'thumb' }}"  alt="{{ item.product.featured_image.alt | escape }}" />
  {% endif %}           
</a>

Would you mind notating where one should implement this code for proper functioning? Thanks!

This snippet can replace the product thumbnail image in cart.liquid

Hey Brad,
New to all this coding, but have a good understanding. Are we just adding this code to the cart.liquid? or are we removing some code and replacing it with this? Your help would be amazing. Thank you!