Hello Ainun, let me give you some overview for you introductory paragraph.
The picturesdiagrams highlight a description with regard to some steps that took place in a headland as a result of coastal erosion through the sea.erosion of a headland phases . Clearly, it can be seen that the overhanging a headland at the top cracks and sea waves attack the zone of weak areas beneath a headland (you can end up your overview here or you add with the further explanation), (and this process consists of there are four phases)of a headline erosion as a result of rock erosion which took a place in a cliff face .
(1) overview; you need not only to explain how many steps that it took, but also you should cover the overall information on the diagram.
Thank you. Good Luck!! :)