<div class="composition">

<img
  srcset="img/img-1.jpg 300w, img/img-1-large.jpg 1000w"
  sizes="(max-width: 56.25em) 20vw, (max-width: 37.5em)  30vw, 300px"
  alt="Photo 1"
class="composition__photo composition__photo--p1"
src="img/img-1-large.jpg" />

</div>