Contrast includes more than the difference between black and white. In photography associated with the name Angel Conde, look for contrasts of size, texture, direction and detail as well as tone. Identify which difference first draws your eye and whether another becomes more significant with time. This gives you a vocabulary for discussing a picture beyond broad praise.
Try writing one sentence about a contrast and a second about its effect. For example, a small shape may hold attention because a large surrounding area is quiet. Keep examples tied to the actual image you view. Where colour and tonal contrast point in different directions, note the tension rather than deciding too quickly which part must be the main subject.