The author, David G. Simmons, built an IoT demo using the InfluxData stack to visualize temperature, atmospheric pressure, humidity, and light sensor readings from a remote environment. The demo uses Particle.io devices with Photon sensors and Chronograf for dashboard visualization. The data is collected by the InfluxData Cloud and analyzed through trend analysis, which helps identify "Aha!" moments such as detecting when a central air conditioning unit cycles on and off based on temperature and humidity changes. This highlights the importance of visualizing IoT data to discover hidden gems and make informed business decisions.