Lightning demos are a great way to get the entire group to find apps and products that could be inspirations for ours. No, this doesn't mean just "copy your competitors".
Look for products from other domains that solve a similar problem for users as the app you're working on. For instance, both food delivery and fashion e-commerce apps solve a similar problem for users: find a thing that works best for them.
A lightning demo works by quickly covering the product, emphasizing the core features and functionality. It is best to start with a primary use case flow or two and walk others through it, describing each relevant feature along the way in brief detail.
Our ultimate workshop template covers the goals and the flow of this workshop exercise. → FigJam