I’m glad you were able to get back to the imagery and that it now works for you. It’s all about the timing, I suppose.
I agree – it’s odd to hear something different from the same recording, but it does happen to people all the time. I think it has to do with the fact that you’re in this drifty, daydreamy, immersive mind-state as you listen, and that’s the perfect condition for your ingenious mind to pick up what it needs to hear at that moment and ignore the rest.
There are many layers of ideas and images in any one of our guided imagery programs for you (or your unconscious) to choose from. And since your internal situation is changing all the time, what gets tuned into from that recording is going to be different from time to time. It is pretty magical, I agree. Hats off to our amazing brains, I say!