I think it has beauty and magic. You have pitched it right for the age group. Your style is gentle and appealing and if I were still working in publishing it would be something I would choose to reply to more personally - rather than the standard 'not right for our list' type letter.
It is, however, very tricky to write rhyming text that scans well and reads aloud well. I think you need to do some more work on that. At the moment it will make readers stumble. Read Tyrannosaurus Drip for an example of a well-done rhyming text.
Also I think you need a stronger ending and possibly a change to the format somewhere in the middle.
By 'stronger ending' I mean a really clear, tying it all up type of finale.
So to summarise, I think you have a beautiful idea and an appealing writing style. I also think you need to do more work on this or get some more practice in, and read some popular texts to see what's out there at the moment.
I would add that it's perceived as being harder to sell picture book texts without a strong plot at the moment. The more 'thoughtful' ones are not being picked up as much. That's not to say the trend won't change, or that you shouldn't be writing them!