Interesting discussion. I have heard of teachers who relate essay writing to a candy or sweet, but I have not heard essays being related to a lolly. I suppose the same principal applies, however. The different sections of the lolly relate to the different sections of the essay, with the top section relating to the introduction, the middle chunk relating to the body of your essay, and the final section relating to your conclusion. Is this what you were refering to? There are a number of illustrations like this that help us remember how to write an essay and emphasise the importance of structure. Of course, writing an essay is not just about knowledge, but also a lot of it is knowing about the various conventions of the essay, and how it should be written in essay format. Writing a good essay is much more than just knowing about the topic you are writing about, so such models and illustrations become incredibly important to help students remember this.