Can you please explain to me what the significance of this song is?

I had a girlfriend who very nearly ruined my life who was obsessed with this song, and Kate Bush generally. Kate Bush is obviously very into witchy stuff.

But some explanation on the significance would be much appreciated. This ex of mine was always trying to load everything with "symbolic significance". She was also mad as a hatter, and a terrible person, but I've always wondered what, if anything, she was trying to signify.

Honestly, I hate everything about Kate Bush so much that I can't even trouble myself to try to listen all the way through, and most of her fans generally don't understand enough about occultism to give a useful explanation.