Seteamos un alto fijo al contenedor en el que se va a incluir el componente 'fluid-image'.
<a href="#" class="fluid-image">
<span class="fluid-image__bg fluid-image__bg--blur" style="background-image: url('your-image-url')"></span>
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<span class="fluid-image__bg fluid-image__bg--blur" style="background-image: url('your-image-url')"></span>
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<span class="fluid-image__bg fluid-image__bg--blur" style="background-image: url('your-image-url')"></span>
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<span class="fluid-image__bg fluid-image__bg--blur" style="background-image: url('your-image-url')"></span>
<img class="fluid-image__img" src="your-image-url" alt="">
</a>
<a href="#" class="fluid-image">
<img class="fluid-image__img" src="your-image-url" alt="">
</a>