I like this film. There are only a few films with fantasy themes like this right now. This film reminded me of "Lady in the Water" directed by Ishana's father, M. Night Shyamalan, which I also really liked. Ishana the director has a vision like her father. She opens up our imagination about the fairy tale world we loved as children. A world where things are magical, beautiful, and full of love, but just like the real world we live in now has things that are ugly, envious, and sad.
The mirror may symbolize two different worlds on each side. Mirrors also imitate what we do. So in this film, the creatures try to imitate what humans do so that they can become or even replace these humans. This theme also appears in Jordan Peele's "Us", where there is an underground world that is a mirror of the world above.
This film also shows that it is very difficult for humans to coexist with other creatures. "The Watchers" who were once gods, became guides, and even lived side by side with humans, were finally removed by humans. Humans will not accept something that has more power than them. And "The Watchers", who were initially good creatures, eventually turned evil as a result of being locked up.
I don't care about the negative reviews of film critics, because everyone has their taste. And it also comes down to individual preference. I found this film to be very entertaining overall, which should be the main goal of all films. And if this film makes you happy, like it did me, that's enough.