Ah, well you're probably not going to be a fan of the below, then, Birty!
Best look away right NOW!!........
Well, I think the whole thing could maybe be about the co-existence of varying states of mind and 'mood'- for both the film and the audience. I don't think, as a whole, the film has one set thing it is relating to us in terms of a story. Feels a bit more abstract than that.
You have the constant 'mood' of the rather chirpy overlaying song, but then moods within the actual film that don't match it at all. The character in it seems to be in altered frames of mind throughout. He's, at times, curious, introspective, frustrated, distressed.... Think he has come from a funeral, but think all that about the dark clothes is just representative of the fact that it's the character that should be concentrated on above all else. He may be someone with all these complexes of thought, but he's just one man; the constant in the film to match the constant of the music. We have to take his feelings and use them to try to work the character out.
With the apple, think his eating it, and in the way that he does, is just representative of what the character is feeling in that particular moment. Maybe there's also a connection to an apple being a 'natural' food he's eating in a 'natural' setting. He could be devouring the apple as he is 'devouring' the natural aspect of where he is.
Maybe the umbrella isn't anybody's in particular (doesn't need to be, as it's just a 'prop' for the character's frame of mind)....though I'm obviously missing the significance of the rope! Will need a clue on that one!
Think he has suffocated himself at the end, though it feels like it's happened 'accidentally'...however that may be....and whatever his 'state of mind' was at the end!
Then there's the feelings of the audience....as they try to work out what it's all about!
Perhaps?!
xx Joanna xx