Interesting.

It is rather unlikely that Christina Rossetti intended this to be a rationalist quote in a sense we would identify with. I do read it as an argument for scientific realism and belief in the implied invisible, but it seems likely that she was merely being poetic or that she was making a pro-religion argument, given her background. Of course the beauty of this system is that if someone quotes this to you as an argument for God (or anything), you can ask them what the leaves and trees are for their wind and thus get at their true argument.

Furthermore, the context in which I first read it is the video game Braid, juvpu cerfragrq vg va gur pbagrkg bs gur chefhvg bs fpvrapr. I would highly recommend this game, by the way.