The talk was about using the Vitamin library for building top bars in mobile applications. The speaker talked about the advantages of using Vitamin over material design, such as having a more oriented contract and using a declarative way of declaring components. They also discussed the parameters used in Vitamin's top bar components, including API slots and colors, as well as the importance of accessibility in the design system. The speaker also mentioned the tokenization of components and the ability to use both Vitamin and Material in mobile applications. The talk ended with a Q&A session.