*{
    margin: 0;
    padding: 0;
}
body{
    position: absolute;
    width: 100%;
    height: 100vh;
    min-height: 100vh;
    background: url(img1.jpg);
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
    overflow: hidden;
}
span{
    display: block;
    position: absolute;
    width: 150px;
    height: 150px;
    background: url(img2.jpg);
    background-repeat: no-repeat;
    background-position: center center;
    background-attachment: fixed;
    background-size: cover;
    pointer-events: none;
    border-radius: 50%;
}