.hero .hero-media {
  background:none;
}

.slick-1 {
  background-image:url(//s3.amazonaws.com/imagescloud/images/home/20170501-m.jpg);
}

@media only screen and (min-width: 991px) {
  .hero .hero-media {
    background:none;
  }
  
  .slick-1 {
    background-image:url(//s3.amazonaws.com/imagescloud/images/home/20170501.jpg);
  }
}