Extra girl, Arantxa Ayala, claimed to be terrified of the instruction of holding a balloon during the taking-picture scene because she's afraid of them.
The song "María" by La Oreja de Van Gogh was played on set so actress Mafer Gonzalez could cry easier while filming.
Even though this story is set in the early 50s, there are props like a Canon camera (made in the 70s), a modern turntable (sold in the 90s), and a vinyl disc of Sgt. Pepper's Lonely Hearts Club Band by The Beatles (released in 1967).
The audio was recorded on Carlos' iPhone 11 and a wired lavaliere.
The composer, Sergio Itzcoatl, made a cameo as a photographer in the party scene.