When writing about your work, you need to explain what the work is representing and the journey throughout. If you are designing someone else’s brand, you need to explain a brief history about it and what the brief is about.
What was the goal/point? What ideas did you get for it? What specific details did you include and why? What themes did you use?
If you included other features, be sure to explain why you introduced other features alongside with it that compliment what you have made. If the packaging were made into an animation, you would need to explain who helped you create it and what the idea behind it was about.
When you are talking about the piece of work, it has to stay precise and keep it simple. Personally, I prefer the way that Sagmeister & Walsh and Pearlfisher have described their work. What they have written is precise and to the point, only explaining the details which viewers only need to see.