The commodity presentation will describe the website content (text, images and other media), explain what form it will take, how it will be organised and how it can be found within the site. You will need to identify your target audience and explain how you have designed the content for them specifically, taking a user-centred design approach.
You can demonstrate your target audience by developing user personas (2-3 should suffice) and you should also consider the user journey, based on typical user scenarios.
Commodity is very much to do with user experience (UX) but does not concern itself with visual design. Ultimately, the commodity theme is about identifying your audience and demonstrating how your content and information architecture will satisfy their goals.