Based on name and location, I assume those chargers are in the Bodan public parking, but I cannot find any official website with confirmation. The parking is listed on the town website, so it might not be owned by a private company? https://www.romanshorn.ch/service/dienstleistungen-a-z.html/242/l/de/service/423
The Parkopedia entry says there are charging stations https://ch.parkopedia.com/parken/parkhaus/bodan/8590/romanshorn/