Whether an essay or a reflective statement on studio work, it is a good idea to begin with an introduction. This gives the essential information your reader needs in order to understand what follows. (Even if you are writing for tutors familiar with your work or the topic you are writing about, you should assume that you are writing for a stranger who is intelligent, but not an expert in the subject).
As well as briefly setting out the context of your piece of writing, the role of introduction is to be a map of the piece as a whole. It is where you summarise for the reader what you are going to say.