.bbb-link {
    display: block;
    position: relative;
    width: 2.5rem;
    height: 4rem;
}

.bbb-link img {
    position: absolute;
    top: 0;
    left: 0;
    height: 4rem;
}

.bbb-link :last-child {
    display: none;
}

.bbb-link:hover :last-child{
    display: block;
}