My thoughts
I saw this the other night, loved it. it's not just arbitrary imagery, I can see how one could be put off about that fact that they were expecting a horror film or giallo homage, it's neither.
It sounds corny, but to me it's about loss of innocence. Here's our main character going to Italy to work on a film. He misses his mom, his home, and his family friendly films. Now he's thrust into the real world of jaded people who are bored with their job (receptionist), mean to others (Francesco) and womanizing a holes (Santini). He's bullied and disturbed by the imagery onscreen, but as Santini puts it, 'it's imitates real life'. The rotting fruit is representative of how things get ugly as they get older, life is drained. When Santini offers him the olive, he says 'where I come from, we eat the seed', and Gilderoy does, changing his ways, conforming to their jaded ways. He even almost finds himself yelling at an actress against his will. When that actress is fired and a new one comes in, she's all bright eyed and green, like how he used to be. He's become just like the others... bitter and now speaking dubbed Italian
The breaking point is when is mom sends the disturbing letter about the dead chickens, he realizes there's no escape from the ugly realities of life. What was once a solace is now gone. When he wakes up and finds himself onscreen, he's essentially finding himself becoming one with the harshness in the film, and in the final shot he literally becomes engulfed in the screen.
I had a wild theory that he might be a character from the film, interacting with his makers. I don't think it's that deep though, i could be wrong. There are some details that still don't make sense, leading me to believe there more to it.
Either way, I loved it. Visually its amazing and it spoke to me about life and how we are all rotting fruit