The animated series Half as Interesting explains why it’s okay to take pictures of the Eiffel Tower during the day, but definitely not at night. It all has to do with French law, the Freedom of Panorama provision, copyright expiration terms and the year that major changes were made to the iconic Paris landmark.
…when Eiffel bought the design he bought the copyright too, but then he died in 1923. 70 years after that, in 1993, the copyright lapsed, just like with any other artistic work. …However, the lights on the Eiffel Tower weren’t installed until 1985, therefore, since they’re considered an artistic work, they are well within their copyright term. For this reason, any photo taken at night when the lights are visible is an illegal reproduction of a copyrighted work.