The predecessor of this device was called "Cheap-Thermocam" (https://web.archive.org/web/20121128040746/http://www.cheap-...) and it used a single-spot MLX90614 sensor to create a thermal image by combining the measurements.
Although the project is now 10 years old, there is a good writeup if anybody wants to build it: https://www.instructables.com/Thermal-Camera/