Creating a transparent arrow above image in CSS3

Question

I\'m trying to create an effect where I have a transparent arrow above any image in CSS3. See the following image.

Answer 1

I think you need something like this:

.arrow {
    bottom: -25px; 
    left: 30px; 
    width: 40px;
    height: 40px;
    position: absolute;
    overflow: hidden;
}

.arrow:after {
    content: ' ';
    display: block;
    background: red;
    width: 20px;
    height: 20px;
    transform: rotate(45deg);
    position: absolute;
    top: -19px;
    left: 3px;
    background: #999;
    border: 5px solid rgba(0, 0, 0, 0.2);
    background-clip: padding-box;
}