.image {
	position: relative;
	display: flex;
	justify-content: center;
	align-items: center;
	width: 100%;
    height: 100vh;
	background: url('./Helena.jpg') center center no-repeat;
	transition: all 1s ease;
	background-size: contain; 
	animation: changeBackground 4s infinite;
}

@-webkit-keyframes changeBackground {
   0%,100%  {background-image: url("./Helena.jpg");}
   50% {background-image: url("./Kasia.jpg");}
}

@-moz-keyframes  changeBackground {
   0%,100%  {background-image: url("./Helena.jpg");}
   50% {background-image: url("./Kasia.jpg");}
}

@-o-keyframes  changeBackground {
   0%,100%  {background-image: url("./Helena.jpg");}
   50% {background-image: url("./Kasia.jpg");}
}

@keyframes  changeBackground {
   0%,100%  {background-image: url("./Helena.jpg");}
   50% {background-image: url("./Kasia.jpg");}
}