We conducted a focus group study in order to design and evaluate annotations that could be used to improve online Tai Chi classes. We were inspired by modern computer vision techniques including human pose estimation, human activity recognition, and object segmentation to design visual annotations that can be overlayed on an instructor’s video during live Tai Chi classes to improve participant understanding and engagement, with a particular focus on older adult Tai Chi practitioners. The focus group, which consisted of older adults with varying levels of experience with online Tai Chi classes, contributed both their feedback and their own ideas to our annotation designs. We were also joined by a Tai Chi instructor who runs online Tai Chi classes for older adults in the McMaster community; they contributed their expertise to our annotation design, and recorded the demonstration videos we used to showcase our annotations. In addition to the particular annotations we developed and evaluated, we also learned valuable guidelines that we can use to design other annotations in the future.