The movie Shape of the Water starts with everything floating around in the house in water. I thought it will be explained somewhere till the end of the film but it wasn't.
What does it really mean? What is the significance of the scene?
The scene is a foreshadowing of a later moment of nears ecstatic intimacy for Eliza, wherein she and the amphibious man purposely flood part of her flat, in order for her to experience the weightlessness of his world.
Less directly, it's a thematic indicator; Eliza eventually comes to discover that her 'world' is underwater; that being her natural, predestined environment upon the discovery of her gills.