Edit in JSFiddle

<div class="container">
  <img src="https://images.unsplash.com/photo-1432059964050-d4eba2ef368a?ixlib=rb-0.3.5&q=80&fm=jpg&crop=entropy&s=c1dbc3d58047ce558b7820745a072b26">
  <div class="two">
    <h1>I <span> &hearts; </span> coffee</h1>
  </div>
</div>

.container {
  width: 100vw;
  height: 100vh;
  .two {
    width: 90vw;
    height: 90vh;
    top: 5vh;
    left: 5vw;
    border: 2px solid #dcdcdc;
    position: absolute;
    z-index: 2;
    display: flex;
		align-items: center;
		justify-content: center;
  }
}

img {
  position: fixed; 
  top: -50%; 
  left: -50%; 
  width: 200%; 
  height: 200%;
}

h1 {
  color: #fff;
  font-size: 4em;
  span {
    color: #681a1a;
    display:inline-block;
  }
}

.scaledIt {
  -webkit-animation: scaleUp .2s infinite;
  -moz-animation: scaleUp .2s infinite;
  -o-animation: scaleUp .2s infinite;
  animation: scaleUp .2s infinite;
}

@-webkit-keyframes scaleUp {
  0% {

    transform:scale(1);
  }
  50% {

    transform:scale(1.3);
  }
  100% {

    transform:scale(1);
  }
}

@-moz-keyframes scaleUp {
  0% {

    transform:scale(1);
  }
  50% {

    transform:scale(1.3);
  }
  100% {

    transform:scale(1);
  }
}

@-o-keyframes scaleUp {
  0% {

    transform:scale(1);
  }
  50% {

    transform:scale(1.3);
  }
  100% {

    transform:scale(1);
  }
}

@keyframes scaleUp {
  0% {

    transform:scale(1);
  }
  50% {

    transform:scale(1.3);
  }
  100% {

    transform:scale(1);
  }
}

$('span').addClass('scaledIt');