A work can have multiple meanings, even unintended meanings. It can even have no intended meaning.

Its creators define its intended meaning, if any. Valid interpretations can create other meaning from it.

I believe the creator determines it and the audience interprets it. Possibly in multiple ways, including some that the artist may have never thought of or intended.

Relies 100% in the author. It’s the one who says “yeah, it mean this” or “yea, it means what you think it does mean”

Yes.