Laughter is on the breeze. But here she sits at her window,
Bars blocking out the scene.

^That paints a clear picture to me. It seems like you're trapped inside your head, and the depression is the thing that surrounds you, mentally. Your eyes are the window. You can see, but you can't move. The bars around you are a prison (depression), and they prevent you from flying, or laughing, or escaping. It takes a lot of strength to break the bars.

Someday she will get the strength to break the iron cage
And stretch her wings and fly

^With this, the speaker is a bird. A weak, small creature. In this place, the bird is supposed to break the iron bars? That's even harder to do if you're as fragile as a bird. But not impossible, as hinted in this piece.

The metaphor is blatantly clear, and this is a gorgeous, visual write. Like everything else written by your hands, it's absolutely breathtaking.

Please never stop writing. You're fantastic.