For an expository essay on blockchain technology aimed at a general audience, incorporating flowchart diagrams would most improve the style of the presentation. A flowchart can effectively represent complex concepts, such as how blockchain transactions are completed and the relationships between different components of blockchain technology. It helps to simplify the information and makes it more accessible for those without subject matter expertise. Additionally, flowcharts can visually guide readers through processes, enhancing their understanding and retention of the material.
While other options like animated graphics, decorative headings, and color photographs can also enhance engagement, flowcharts specifically support the explanatory goal of the essay by clearly illustrating the dynamics of blockchain technology.