You've put in a lot of hard work, and you're almost to your goal: graduation and a degree. You want to commemorate your accomplishments and let everyone know you're ready for the next step in your life. And you get to decide how you want people to remember you.
Your senior pictures are a big part of all this. Just as your graduation is a personal experience, your senior pictures should be too. Use them to show people what's important to you. They're what many people are going to use to remember you - You want to truly be yourself. And look great while you're doing it.