@keyframes myanimation {
    from {
        left: -20%;
    }

    to {
        left: 100%;
    }
}

figure {
    width: 20%;
    max-width: 400px;
    top: 40%;
    position: absolute;
    animation: myanimation 20s infinite;
}

figure
    img {
    width: 100%;
}